I don't beleive the music choice channels are part of the FIOS app channels.
Don't know if this might meet your needs.
RADIO SURE FREE INTERNET WORLDWIDE RADIO
Have had it on my Desktop since October 2013
First used under Windows 7 now migrated to Windows 10
73's for now.
I know from the PC I can stream the Music Choice channels from their website:
What else I have done, is I have hooked up my set top box to my sound system, so I can just leave it playing Music Choice channels without the need for the TV to be turned on.