Actually, I contacted Logitech's corporate tech support and received the following somewhat non-precise answer about Apple's plus songs.
"Regarding your question, the Squeezebox or Duet will play music files in the following audio formats:
"Formats natively supported by the Squeezebox include MP3, FLAC, WAV/AIFF, and WMA (CBR & VBR). There's also non-native support for AAC (M4A, not M4P), Apple Lossless, WMA lossless, Ogg Vorbis, plus other obscure formats like MusePack and Monkey's Audio.
"As long as these files do not have the DRM attachment, the Squeezebox or Duet will play them.
As you will note there is not a specific answer, unless Apple plus songs are encoded as M4A. Thats why I hoped someone on this forum might know the answer.
_________________________
Living Room 24x18 open 1/2 flight up to a raised dining room/hall 24x12
Outlaw 976 pre-pro running 5.1 system
Outlaw 750 for Artison Masterpiece LCR and 2 NHT SuperZeros rears
Velodyne Servo FX-1200
LG OLED65C8PUA via HDMI2 to/from 976 HDMI ARC
Roku Ultra
Samsung BD-D5500 BluRay
Amazon FireStick 4K to 976 Aux HDMI input for Amazon Music Ultra