Trying to find the quality of streaming...looks like Amazon may be using ~256kbps VBR MP3.
Pandora says it uses 64kbps for free streaming and all mobile devices paid or not, and 192kbps for paid PC's.
Don't know what else is out there...
I only recently tried free Pandora as a sort of radio to find new stuff.
The quality is really bad...and many of their "similar" choices are WTF.
If it's actually 256kbps and Amazon actually gets a usable list of music I may use it. If it ends up like their prime video with only 20 crap movies to choose from and no good TV shows then I'm going to avoid it.