Is Apple Music lossless/uncompressed?

I listen to Classical so it’s hard for me to comment on the depth of catalog but I believe that they carry as many tracks as any of the other top claimed services.

  They are indeed lossless but it depends on the playback device.  With the possible exception of Eversolo (and that may be temporary) you can’t stream it directly except with Apple TV, and that will get you mp3 sound(the Apple equivalent-I forgot the acronym for the file format, but it’s the Apple version of mp3).

 Airplay is an improvement over Bluetooth and almost CD quality.  Either option of course throttles High Resolution offerings to a lower resolution.  Chromecast is the best SQ option but you will hit occasional glitches where Google and Apple don’t wish to play nice together, and you will need an Android device for Chromecast 

There is an alternative if using Airplay  - buy a 1st generation AirPort Express off EBay (got mine for $10). Set up to join your existing network. Use the 3mm audio out to connect to your amp/preamp etc. (!st gen AirPort Express are Airplay 1 receivers and the stream from the iPhone will be lossless). Darko's site has additional info. Won't help getting hi-res however. 

From what I understand Apple music streams in ALAC format up to 24/192 resolution.

From support.apple.com:

If you subscribe to Apple Music, you can play and download music encoded using the Apple Lossless Audio Codec (ALAC), which makes files smaller while preserving all of the original data in the file. In Apple Music, lossless music is available in two formats:

• Lossless: Up to 24-bit, 48 kHz

• Hi-Res Lossless: Up to 24-bit, 192 kHz

Albums and songs available in lossless have the Lossless button next to them.

Note: Apple Music and lossless aren’t available in all countries or regions. See the Apple Support article Availability of Apple Media Services.