Music downloaded from Spotify Premium are in OGG format, Apple Music tracks downloaded from iTunes are in M4P format, both are added DRM protected and only playable on it's app and authorized devices.

TunesKit Apple Music Converter can convert the DRM-ed Apple Music files from M4P to DRM-free MP3, AAC, WAV, M4A, M4B and FLAC while preserving the original ID tags and metadata, including track number ...