Music Maker - App Spec

O1 Preview

**SECTION 1 - SUMMARY/OVERVIEW OF THE APP**

**Summary of the App**

"Music Maker" is a React application that enables users to create custom music mixes by uploading MP3 files and combining acapella and instrumental tracks. Users can input up to three MP3 URLs, specify whether each is an acapella or instrumental, and have them processed to adjust their BPM (beats per minute) to the nearest value among 50, 60, 70, 80, or 90. The app then allows users to select compatible tracks based on BPM and mix them together. The final mixed track can be previewed, downloaded, and is displayed alongside previous mixes.

**Overview of Each Page**

1. **Input Page (`InputPage.js`)**:
   - Users enter URLs of up to three MP3 files.
   - Specify for each MP3 whether it's an acapella or instrumental using radio buttons.
   - Upon clicking "Send," the app sends these MP3s to an API (task 29) to adjust their BPMs.

2. **Build Mix Page (`BuildMixPage.js`)**:
   - Displays the processed MP3s returned from the API in a table format.
   - Shows the title, adjusted BPM, and provides a preview player for each track.
   - Users select one acapella and one instrumental to mix.
   - Instrumentals not within ±10 BPM of the selected acapella are greyed out.
   - Upon clicking "Convert," the selected tracks are sent to another API (task 43) to create the mix.

3. **Result Page (`ResultPage.js`)**:
   - Displays the newly mixed MP3 returned from the API after processing.
   - Shows the mix title, BPM, provides a preview player, and includes a download link.
   - Previous mixes are listed in a table, with the most recent mix displayed first.

**Key Technical Considerations**

- **API Integration**:
  - Handle asynchronous API calls to tasks 29 and 43.
  - Manage API response delays, especially since creating the mix may take several minutes.
  - Parse and handle JSON data returned from the APIs.

- **State Management**:
  - Maintain state across pages for user inputs and API responses.
  - Use React Context or another state management solution to pass data between components and pages.

- **User Interface**:
  - Ensure intuitive input forms and selection mechanisms.
  - Implement dynamic UI elements, such as greying out incompatible tracks based on BPM.

- **Error Handling & Validation**:
  - Validate MP3 URLs and user selections.
  - Provide user feedback for API errors, invalid inputs, or timeouts.

- **Loading States**:
  - Indicate processing times with loading spinners or messages during API calls.

- **Audio Playback**:
  - Utilize HTML5 audio elements for previewing tracks and mixes within the app.

---

**SECTION 2 - FILE TREE**

```
src/
│
├── components/
│   ├── Navbar.js
│   ├── Navbar.css
│   ├── MP3Input.js
│   ├── MP3Input.css
│   ├── TrackTable.js
│   ├── TrackTable.css
│   ├── AudioPlayer.js
│   ├── AudioPlayer.css
│   ├── LoadingSpinner.js
│   └── LoadingSpinner.css
├── pages/
│   ├── InputPage.js
│   ├── InputPage.css
│   ├── BuildMixPage.js
│   ├── BuildMixPage.css
│   ├── ResultPage.js
│   └── ResultPage.css
├── services/
│   └── api.js
├── App.js
└── App.css
```

---

**SECTION 3 - SUMMARY OF THE FILES**

1. **App.js**
   - **Summary**: The root component that sets up routing between pages and includes the `Navbar`.
   - **Dependencies**: React Router (`react-router-dom`), `Navbar.js`, `App.css`.
   - **Dependent Files**: All pages rendered via routes.
   - **Notes**: Ensure proper routing and inclusion of global components like `Navbar`.

2. **App.css**
   - **Summary**: Global styles applied throughout the app.
   - **Dependencies**: None.
   - **Dependent Files**: `App.js`.
   - **Notes**: Include CSS resets and global theming.

3. **services/api.js**
   - **Summary**: Contains API functions to interact with tasks 29 and 43.
   - **Dependencies**: Axios or Fetch API for HTTP requests.
   - **Dependent Files**: `InputPage.js`, `BuildMixPage.js`, `ResultPage.js`.
   - **Notes**: Handle asynchronous calls and manage responses and errors.

4. **components/Navbar.js**
   - **Summary**: Navigation bar with links to the `InputPage`, `BuildMixPage`, and `ResultPage`.
   - **Dependencies**: `react-router-dom` for navigation, `Navbar.css`.
   - **Dependent Files**: `App.js`.
   - **Notes**: Implement responsive design and active link highlighting.

5. **components/Navbar.css**
   - **Summary**: Styles specific to the `Navbar` component.

6. **components/MP3Input.js**
   - **Summary**: Allows users to input an MP3 URL and select acapella or instrumental.
   - **Dependencies**: `MP3Input.css`.
   - **Dependent Files**: `InputPage.js`.
   - **Notes**: Validate inputs and manage component state.

7. **components/MP3Input.css**
   - **Summary**: Styles specific to the `MP3Input` component.

8. **components/TrackTable.js**
   - **Summary**: Displays a list of tracks with title, BPM, and preview player; allows selection for mixing.
   - **Dependencies**: `TrackTable.css`, `AudioPlayer.js`.
   - **Dependent Files**: `BuildMixPage.js`.
   - **Notes**: Implement logic to grey out incompatible tracks based on BPM differences.

9. **components/TrackTable.css**
   - **Summary**: Styles specific to the `TrackTable` component.

10. **components/AudioPlayer.js**
    - **Summary**: Reusable component to play MP3 files using HTML5 audio.
    - **Dependencies**: `AudioPlayer.css`.
    - **Dependent Files**: `TrackTable.js`, `ResultPage.js`.
    - **Notes**: Ensure cross-browser compatibility and customize player controls as needed.

11. **components/AudioPlayer.css**
    - **Summary**: Styles specific to the `AudioPlayer` component.

12. **components/LoadingSpinner.js**
    - **Summary**: Displays a loading indicator during API calls.
    - **Dependencies**: `LoadingSpinner.css`.
    - **Dependent Files**: `ResultPage.js`, potentially others during loading states.
    - **Notes**: Make sure it doesn't obstruct user interaction elsewhere on the page.

13. **components/LoadingSpinner.css**
    - **Summary**: Styles specific to the `LoadingSpinner` component.

14. **pages/InputPage.js**
    - **Summary**: Collects MP3 URLs and track types from the user.
    - **Dependencies**: `MP3Input.js`, `api.js`, `InputPage.css`.
    - **Dependent Files**: Rendered within `App.js`.
    - **Notes**: Manage multiple `MP3Input` components and handle form submission.

15. **pages/InputPage.css**
    - **Summary**: Styles specific to the `InputPage`.

16. **pages/BuildMixPage.js**
    - **Summary**: Allows users to select tracks to mix from the processed MP3s.
    - **Dependencies**: `TrackTable.js`, `api.js`, `BuildMixPage.css`.
    - **Dependent Files**: Rendered within `App.js`.
    - **Notes**: Implement selection logic and send selected tracks to the API.

17. **pages/BuildMixPage.css**
    - **Summary**: Styles specific to the `BuildMixPage`.

18. **pages/ResultPage.js**
    - **Summary**: Displays the final mixed track and a list of previous mixes.
    - **Dependencies**: `AudioPlayer.js`, `LoadingSpinner.js`, `api.js`, `ResultPage.css`.
    - **Dependent Files**: Rendered within `App.js`.
    - **Notes**: Handle delayed API response and update the UI accordingly.

19. **pages/ResultPage.css**
    - **Summary**: Styles specific to the `ResultPage`.

---

**SECTION 4 - CODING SESSION PLAN**

**Session 1 - Write `App.js` and `App.css`**

- **Files**: `App.js`, `App.css`
- **Summary**:
  - *App.js*: Set up the main application component with React Router for navigation between `InputPage`, `BuildMixPage`, and `ResultPage`. Include the `Navbar` component on all pages.
  - *App.css*: Define global styles for the app, including basic layout and theming.
- **Dependencies**: React Router (`react-router-dom`), `Navbar.js`.
- **Notes**: Ensure routing is correctly configured and the `Navbar` is consistently displayed across all pages.

---

**Session 2 - Write `api.js`**

- **Files**: `api.js`
- **Summary**:
  - Define functions to interact with the external APIs (tasks 29 and 43).
  - Implement `processMP3s` function to send MP3 URLs to task 29.
  - Implement `createMix` function to send selected tracks to task 43.
- **Dependencies**: Axios or Fetch API for HTTP requests.
- **Notes**: Handle asynchronous operations, manage API endpoints and payload structures, and include error handling for network requests.

---

**Session 3 - Create Core Components (Part 1)**

- **Files**:
  - `Navbar.js`, `Navbar.css`
  - `MP3Input.js`, `MP3Input.css`
- **Summary**:
  - *Navbar*: Create navigation links to each page with active link styling.
  - *MP3Input*: Develop a component for users to input MP3 URLs and select acapella or instrumental.
- **Dependencies**: `react-router-dom` for navigation in `Navbar`, state management in `MP3Input`.
- **Notes**:
  - In `Navbar`, ensure responsive design for various screen sizes.
  - In `MP3Input`, validate URLs and limit the number of inputs.

---

**Session 4 - Create Core Components (Part 2)**

- **Files**:
  - `TrackTable.js`, `TrackTable.css`
  - `AudioPlayer.js`, `AudioPlayer.css`
  - `LoadingSpinner.js`, `LoadingSpinner.css`
- **Summary**:
  - *TrackTable*: Display tracks with selection options and implement BPM compatibility logic.
  - *AudioPlayer*: Create a reusable audio player component for MP3 previews.
  - *LoadingSpinner*: Indicate loading states during API calls.
- **Dependencies**: Data from API responses, `AudioPlayer` used within `TrackTable`.
- **Notes**:
  - Ensure `TrackTable` correctly greys out incompatible tracks.
  - `AudioPlayer` should have customizable controls and fallback support.
  - `LoadingSpinner` should be visually distinct and non-intrusive.

---

**Session 5 - Create Pages (Part 1)**

- **Files**:
  - `InputPage.js`, `InputPage.css`
- **Summary**:
  - Assemble the input page using multiple `MP3Input` components.
  - Handle submission to send MP3 data to the API via `processMP3s` function.
- **Dependencies**: `MP3Input.js`, `api.js`.
- **Notes**:
  - Manage state for multiple inputs.
  - Navigate to `BuildMixPage` after successful API response.

---

**Session 6 - Create Pages (Part 2)**

- **Files**:
  - `BuildMixPage.js`, `BuildMixPage.css`
  - `ResultPage.js`, `ResultPage.css`
- **Summary**:
  - *BuildMixPage*: Display processed tracks using `TrackTable` and handle track selection and submission to the API via `createMix`.
  - *ResultPage*: Display the final mix using `AudioPlayer`, show a loading state with `LoadingSpinner`, and list previous mixes.
- **Dependencies**: `TrackTable.js`, `AudioPlayer.js`, `LoadingSpinner.js`, `api.js`.
- **Notes**:
  - Ensure BPM compatibility logic works during selection in `BuildMixPage`.
  - In `ResultPage`, handle delayed responses and update the UI seamlessly.

---

**Session 7 - Update `App.js` with Final Integrations**

- **Files**: Update `App.js` (if necessary), potentially set up global state management (e.g., using Context API).
- **Summary**:
  - Finalize routing and state passing in `App.js`.
  - Implement global state to manage data across pages, if not already done.
- **Dependencies**: All components and pages.
- **Notes**:
  - Ensure all navigation flows are smooth.
  - Address any issues with data persistence between pages.
  - Optimize for performance and responsiveness.

---

By following this plan, the app can be developed systematically over seven coding sessions, ensuring all components and pages are properly integrated and functional.

Sonnet

SECTION 1 - SUMMARY/OVERVIEW OF THE APP

The Music Maker app is a three-page React application that allows users to create custom music mixes using acapella and instrumental tracks. Users can upload up to three MP3 files, which are then processed by an external API to adjust their BPM. The app then enables users to select compatible tracks and mix them together, resulting in a new, combined MP3 file.

Pages:
1. Input Page: Users can enter URLs for up to three MP3 files and specify whether each is an acapella or instrumental.
2. Build Mix Page: Displays processed tracks with their details and allows users to select compatible tracks for mixing.
3. Final Mix Page: Shows the resulting mixed tracks with playback and download options.

Key technical considerations:
- Integration with two external APIs for processing MP3 files and creating mixes
- Implementing BPM-based track compatibility logic
- Managing asynchronous operations for API calls and file processing
- Implementing HTML5 audio players for track previews

SECTION 2 - FILE TREE

src/
│
├── components/
│   ├── AudioPlayer.js
│   ├── AudioPlayer.css
│   ├── TrackInput.js
│   ├── TrackInput.css
│   ├── TrackList.js
│   ├── TrackList.css
│   ├── MixSelector.js
│   └── MixSelector.css
├── pages/
│   ├── InputPage.js
│   ├── InputPage.css
│   ├── BuildMixPage.js
│   ├── BuildMixPage.css
│   ├── FinalMixPage.js
│   └── FinalMixPage.css
├── services/
│   └── api.js
├── App.js
└── App.css

SECTION 3 - SUMMARY OF THE FILES

1. App.js
   - Main component that sets up routing and overall app structure
   - Dependencies: React Router, all page components
   - Other files depend on this for routing

2. App.css
   - Global styles for the app
   - No dependencies, but other CSS files may import from here

3. api.js
   - Contains functions for making API calls to process and mix tracks
   - Dependencies: None
   - Other components will depend on this for API interactions

4. AudioPlayer.js & AudioPlayer.css
   - Reusable component for playing audio previews
   - Dependencies: None
   - Used by TrackList and FinalMixPage

5. TrackInput.js & TrackInput.css
   - Component for inputting track URLs and selecting track type
   - Dependencies: None
   - Used by InputPage

6. TrackList.js & TrackList.css
   - Component for displaying a list of tracks with their details
   - Dependencies: AudioPlayer
   - Used by BuildMixPage and FinalMixPage

7. MixSelector.js & MixSelector.css
   - Component for selecting compatible tracks to mix
   - Dependencies: None
   - Used by BuildMixPage

8. InputPage.js & InputPage.css
   - Page component for inputting initial track information
   - Dependencies: TrackInput, api.js
   - No other files depend on this

9. BuildMixPage.js & BuildMixPage.css
   - Page component for selecting and mixing tracks
   - Dependencies: TrackList, MixSelector, api.js
   - No other files depend on this

10. FinalMixPage.js & FinalMixPage.css
    - Page component for displaying final mixed tracks
    - Dependencies: TrackList, AudioPlayer, api.js
    - No other files depend on this

SECTION 4 - CODING SESSION PLAN

Session 1 - Write `App.js` and `App.css`
Files: App.js, App.css
Summary: Set up the main app structure and routing
Dependencies: React Router
Watch out for: Proper route setup for all three pages

Session 2 - Write `api.js`
Files: api.js
Summary: Implement API call functions for processing and mixing tracks
Dependencies: None
Watch out for: Proper error handling and response parsing

Session 3 - Create Core Components (Part 1)
Files: AudioPlayer.js, AudioPlayer.css, TrackInput.js, TrackInput.css
Summary: Create components for audio playback and track input
Dependencies: None
Watch out for: Proper audio controls implementation and input validation

Session 4 - Create Core Components (Part 2)
Files: TrackList.js, TrackList.css, MixSelector.js, MixSelector.css
Summary: Create components for displaying track lists and selecting tracks to mix
Dependencies: AudioPlayer component
Watch out for: Implementing BPM compatibility logic in MixSelector

Session 5 - Create Pages (Part 1)
Files: InputPage.js, InputPage.css
Summary: Create the initial input page for the app
Dependencies: TrackInput component, api.js
Watch out for: Proper state management for multiple track inputs

Session 6 - Create Pages (Part 2)
Files: BuildMixPage.js, BuildMixPage.css, FinalMixPage.js, FinalMixPage.css
Summary: Create the build mix and final mix pages
Dependencies: TrackList, MixSelector, AudioPlayer components, api.js
Watch out for: Managing state between pages and handling API responses

Session 7 - Update `App.js` with Final Integrations
Files: App.js, App.css
Summary: Final updates to main app structure and global styles
Dependencies: All previously created components and pages
Watch out for: Ensuring proper navigation between pages and consistent styling

Gemini

## SECTION 1 - SUMMARY/OVERVIEW OF THE APP

This Music Maker app allows users to combine acapella and instrumental tracks.  Users upload up to three MP3s, specifying the type (acapella or instrumental) on the input page. These are sent to an API which returns time-stretched versions at standardized BPMs. On the build mix page, users select one acapella and one instrumental with BPMs within 10 of each other. These selections are sent to the API for mixing.  The final page displays the newly mixed track with download and preview options.

**Pages:**

* **Input:**  Handles MP3 URL input and type selection, submits data to the first API call.
* **Build Mix:** Displays processed tracks, allows selection of compatible acapella and instrumental, submits selections to the second API call.
* **Mix Output:** Displays the final mixed track, provides download link, and playback functionality.

**Key Technical Considerations:**

* Handling asynchronous API calls and managing loading states.
* Implementing BPM-based selection logic.
* Embedding and managing HTML5 audio players.
* Efficiently handling potential API errors and displaying user-friendly messages.

## SECTION 2 - FILE TREE

```
src/
│
├── components/
│   ├── UploadForm.js
│   ├── UploadForm.css
│   ├── TrackList.js
│   ├── TrackList.css
│   ├── AudioPlayer.js
│   └── AudioPlayer.css
│   ├── MixForm.js
│   └── MixForm.css
│   ├── DownloadLink.js
│   └── DownloadLink.css
├── pages/
│   ├── InputPage.js
│   ├── InputPage.css
│   ├── BuildMixPage.js
│   └── BuildMixPage.css
│   ├── MixOutputPage.js
│   └── MixOutputPage.css
├── services/
│   └── api.js
├── App.js
└── App.css
```

## SECTION 3 - SUMMARY OF THE FILES

* **App.js:** Main application component, handles routing and page navigation.
    * Dependencies: React Router, all pages.
    * Dependent on by: All pages.

* **App.css:**  Styling for the main application layout.
    * Dependencies: None.

* **api.js:**  Contains functions for making API calls.
    * Dependencies: None.
    * Dependent on by: `InputPage`, `BuildMixPage`

* **components/UploadForm.js:** Component for uploading MP3 URLs and type selection.
    * Dependencies:  `api.js`.
    * Dependent on by: `InputPage`

* **components/UploadForm.css:** Styling for UploadForm.

* **components/TrackList.js:** Component for displaying a list of tracks with BPM and preview player.
    * Dependencies: `AudioPlayer`
    * Dependent on by: `BuildMixPage`, `MixOutputPage`

* **components/TrackList.css:** Styling for TrackList.

* **components/AudioPlayer.js:** Reusable HTML5 audio player component.
    * Dependencies: None.
    * Dependent on by: `TrackList`.

* **components/AudioPlayer.css:** Styling for AudioPlayer.

* **components/MixForm.js:** Form for selecting acapella and instrumental tracks to mix.
    * Dependencies: `api.js`.
    * Dependent on by: `BuildMixPage`.

* **components/MixForm.css:** Styling for MixForm.

* **components/DownloadLink.js:** Component for displaying a download link for the mixed track.
    * Dependencies: None.
    * Dependent on by: `MixOutputPage`

* **components/DownloadLink.css:**  Styling for DownloadLink.

* **pages/InputPage.js:**  The initial input page.
    * Dependencies: `UploadForm`, `api.js`.
    * Dependent on by: `App.js`.

* **pages/InputPage.css:**  Styling for InputPage.

* **pages/BuildMixPage.js:** Page for selecting tracks to mix.
    * Dependencies: `TrackList`, `MixForm`, `api.js`.
    * Dependent on by: `App.js`.

* **pages/BuildMixPage.css:** Styling for BuildMixPage.

* **pages/MixOutputPage.js:** Page for displaying the final mixed track.
    * Dependencies: `TrackList`, `DownloadLink`.
    * Dependent on by: `App.js`.

* **pages/MixOutputPage.css:** Styling for MixOutputPage.

## SECTION 4 - CODING SESSION PLAN

* **Session 1 - Write `App.js` and `App.css`**
    * Files: `App.js`, `App.css`
    * Summary: Set up routing, navigation, and basic app structure.
    * Dependencies: React Router.
    * Watch out for: Correct routing configuration and import paths for pages.

* **Session 2 - Write `api.js`**
    * Files: `api.js`
    * Summary: Implement API call functions for both API endpoints (tasks 29 and 43).
    * Dependencies:  None.
    * Watch out for: Correctly handling API responses and potential errors, managing asynchronous operations.

* **Session 3 - Create Core Components (Part 1)**
    * Files: `UploadForm.js`, `UploadForm.css`, `AudioPlayer.js`, `AudioPlayer.css`
    * Summary: Create the upload form and audio player components
    * Dependencies:  `api.js` (for UploadForm)
    * Watch out for: In Uploadform, ensure correct data submission format for the API call. In AudioPlayer, handle different audio formats and loading states.

* **Session 4 - Create Core Components (Part 2)**
    * Files: `TrackList.js`, `TrackList.css`, `MixForm.js`, `MixForm.css`, `DownloadLink.js`, `DownloadLink.css`
    * Summary: Create the track list, mix form and download link components
    * Dependencies: `AudioPlayer` (for `TrackList`), `api.js` (for `MixForm`)
    * Watch out for: In TrackList, ensure efficient rendering of potentially multiple audio players. In MixForm, implement the BPM-based selection logic.

* **Session 5 - Create Pages (Part 1)**
    * Files: `InputPage.js`, `InputPage.css`
    * Summary: Create the input page
    * Dependencies:  `UploadForm`, `api.js`.
    * Watch out for: Correct integration of the UploadForm component and handling the API response.

* **Session 6 - Create Pages (Part 2)**
    * Files: `BuildMixPage.js`, `BuildMixPage.css`, `MixOutputPage.js`, `MixOutputPage.css`
    * Summary: Create the mix build page and the mix output page..
    * Dependencies: `TrackList`, `MixForm`, `api.js` (for `BuildMixPage`),  `TrackList`, `DownloadLink` (for `MixOutputPage`)
    * Watch out for: In BuildMixPage, ensure proper integration of TrackList and MixForm and handling the API response.

* **Session 7 - Update `App.js` with Final Integrations**
    * Files: `App.js`, `App.css`
    * Summary: Finalize routing, navigation, and component integration in App.js, and add any necessary final styling in App.css..
    * Dependencies: All pages and components.
    * Watch out for: Ensure all routes are correctly configured and all components are correctly integrated. Add any necessary error handling or loading state management.

GPT 4O

Certainly! Let's create a plan for the Music Maker app following the detailed blueprint you've requested.

---

### SECTION 1 - SUMMARY/OVERVIEW OF THE APP

The **Music Maker** app is a React application that allows users to manipulate and mix MP3 tracks. The app consists of three main pages. Users can input up to three MP3 URLs, specify their type (acapella or instrumental), and send them to an API for BPM conversion. The second page allows users to select BPM-compatible tracks to mix. The final page displays the newly mixed track for download and playback.

- **Input Page:** Users input MP3 URLs, specify their type, and send requests to an external API to adjust the BPM.
- **Build Mix Page:** Users can select acapella and instrumental tracks with similar BPMs to mix them through the API.
- **Output Page:** Displays the mixed tracks, providing a download link and audio preview.

**Key Technical Considerations:**
- Integrating an API to convert and mix MP3s based on user input.
- Handling API responses to update React state and render UI elements.
- Ensuring compatible BPM selection logic.
- Basic styling using vanilla CSS and React components.

---

### SECTION 2 - FILE TREE

```plaintext
src/
│
├── components/
│   ├── MP3InputForm.js
│   ├── MP3InputForm.css
│   ├── TrackTable.js
│   ├── TrackTable.css
│   ├── PreviewPlayer.js
│   └── PreviewPlayer.css
├── pages/
│   ├── InputPage.js
│   ├── InputPage.css
│   ├── BuildMixPage.js
│   ├── BuildMixPage.css
│   ├── OutputPage.js
│   └── OutputPage.css
├── services/
│   └── api.js
├── App.js
├── App.css
```

---

### SECTION 3 - SUMMARY OF THE FILES

1. **App.js**
   - Sets up routing and structure for the app.
   - Depends on page and component imports for rendering.

2. **App.css**
   - Basic styling for global elements and layout.

3. **api.js**
   - Handles API calls to external MP3 processing service.
   - Dependent on the API specifications and endpoints.

4. **components/MP3InputForm.js**
   - A form for users to input MP3 URLs and select options.
   - Dependent upon state management for form data.

5. **components/MP3InputForm.css**
   - Styles specific to the MP3 input form.

6. **components/TrackTable.js**
   - Displays a table of tracks with BPM and preview.
   - Depends on API data for rendering table rows.

7. **components/TrackTable.css**
   - Styles specific to the track table.

8. **components/PreviewPlayer.js**
   - Provides a media player for track previews.
   - Requires audio file URLs for playback.

9. **components/PreviewPlayer.css**
   - Styles specific to the preview player.

10. **pages/InputPage.js**
    - Renders the MP3InputForm and invokes API call.
    - Initial page that captures user input.

11. **pages/InputPage.css**
    - Styles for the input page layout.

12. **pages/BuildMixPage.js**
    - Allows users to select compatible tracks for mixing.
    - Depends on data from the input step.

13. **pages/BuildMixPage.css**
    - Styles for organizing track selection UI.

14. **pages/OutputPage.js**
    - Displays mixed tracks with download and preview.
    - Depends on result data from the mixing API.

15. **pages/OutputPage.css**
    - Styles for the finalized output display page.

---

### SECTION 4 - CODING SESSION PLAN

#### **Session 1 - Write `App.js` and `App.css`**
- **Filename(s):** `App.js`, `App.css`
- **Summary:** Set up the main app structure with React Router to handle page navigation.
- **Dependencies:** None initially; foundational setup.
- **Watch Out For:** Ensure routing is correctly established for the placeholders of all pages.

#### **Session 2 - Write `api.js`**
- **Filename(s):** `api.js`
- **Summary:** Implement API call functions for processing MP3s.
- **Dependencies:** Requires endpoint information for API calls.
- **Watch Out For:** Ensure data handling for sending and receiving JSON is correct.

#### **Session 3 - Create Core Components (Part 1)**
- **Filename(s):** `MP3InputForm.js`, `MP3InputForm.css`, `PreviewPlayer.js`
- **Summary:** Create the form for MP3 input and the player for previews.
- **Dependencies:** MP3 Input Form needs connection to state, Preview Player will be used later.
- **Watch Out For:** Form validation and audio handling logic need to be precise.

#### **Session 4 - Create Core Components (Part 2)**
- **Filename(s):** `TrackTable.js`, `TrackTable.css`, `PreviewPlayer.css`
- **Summary:** Set up the table for displaying tracks, finish Preview Player styles.
- **Dependencies:** Track Table relies on structured track data.
- **Watch Out For:** Ensure correct dynamic rendering based on the BPM logic.

#### **Session 5 - Create Pages (Part 1)**
- **Filename(s):** `InputPage.js`, `InputPage.css`
- **Summary:** Code the initial input page where users submit their MP3s.
- **Dependencies:** Relies on MP3InputForm component.
- **Watch Out For:** Proper handling of form submission to trigger API call.

#### **Session 6 - Create Pages (Part 2)**
- **Filename(s):** `BuildMixPage.js`, `BuildMixPage.css`
- **Summary:** Code the page that lets users select and mix tracks.
- **Dependencies:** Utilizes TrackTable component.
- **Watch Out For:** Ensure correct logic for pairing tracks with compatible BPMs.

#### **Session 7 - Update `App.js` with Final Integrations**
- **Filename(s):** Revisit `App.js` and `App.css`
- **Summary:** Final integration and routing adjustments.
- **Dependencies:** All pages and components developed thus far.
- **Watch Out For:** Ensure the routes elegantly handle all navigation paths and state transitions in the app.

This plan will guide the construction of the Music Maker application across the seven coding sessions described.