Seems like all songs downloaded via Apple Music are DRM'ed w/ Fairplay. You can see it for yourself via ffprobe
available as a part of ffmpeg.
~/Music/iTunes/iTunes Media/Apple Music/${Artist}/${Album}/${Song}.m4p
Metadata:
[…]
Duration: 00:03:51.11, start: 0.000000, bitrate: 286 kb/s
Stream #0:0(eng): Audio: aac (LC) (drms / 0x736D7264), 44100 Hz, stereo, fltp, 265 kb/s (default)
Metadata:
creation_time : 2015-07-02 23:22:52
Stream #0:1: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 600x600 [SAR 300:300 DAR 1:1], 90k tbr, 90k tbn, 90k tbc
Whereas iTunes Match'ed songs are DRM-free.
~/Music/iTunes/iTunes Media/Music/${Artist}/${Album}/${Song}.m4a
Metadata:
[…]
Duration: 00:04:20.20, start: 0.000000, bitrate: 277 kb/s
Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 258 kb/s (default)
Metadata:
creation_time : 1993-08-01 19:45:18
Stream #0:1: Video: png, none(pc), 90k tbr, 90k tbn, 90k tbc