graph TD A[Start: Receive downloaded-mp3-urls] --> B[Initialize AudioSeparator] B --> C[Process First MP3] B --> D[Process Second MP3] B --> E[Process Third MP3] C --> F[Extract Stems - Skill #197] D --> G[Extract Stems - Skill #197] E --> H[Extract Stems - Skill #197] F --> I[vocal1.mp3] F --> J[instrumental1.mp3] G --> K[vocal2.mp3] G --> L[instrumental2.mp3] H --> M[vocal3.mp3] H --> N[instrumental3.mp3] I --> O[Collate & Map - Skill #223] J --> O K --> O L --> O M --> O N --> O O --> P[Structure Final Output] P --> Q[Return vocals-instrumentals-urls]