Which Android app should I use to mix my own purchased music with a streaming library?

Amazon Music is positioned as a hybrid solution for listeners who own digital music files but also want access to a vast streaming catalog. The app's key feature for this use case is the ability to upload personal music purchases—up to 100,000 tracks—to Amazon's cloud. Once uploaded, these tracks appear in the user's library alongside any music saved from the Amazon Music streaming service. This creates a single, consolidated music collection accessible from any device. For real-world use, this means a user can have their old, purchased MP3s from the 2000s sitting in the same playlist as the latest chart hits from the streaming service, all playable offline if downloaded.

However, this integration has notable limitations that are a frequent source of user complaints. The experience differs sharply between the free, ad-supported tier and the paid Music Unlimited subscription. Non-subscribers face significant restrictions, most notably an inability to play their uploaded music in a custom order or use shuffle mode for specific song lists—a pain point clearly expressed in many reviews. The app's organizational tools, like the ability to create multiple personal libraries (e.g., 'Oldies,' 'Workout Mix'), are a strength for managing large collections. While the playback experience for uploaded files won't match the Ultra HD or Dolby Atmos quality available for streaming certain tracks, the convenience of a unified library is a significant draw for users with existing digital collections.