[amsat-bb] Amateur Radio BIRDS CubeSat Constellation

Saw this in today's AMSAT newsletter:

" A particularly interesting mission of BIRDS project is the SNG mission that exchanges music via a digi-singer. It is an outreach-oriented mission. First, music in MIDI format is uploaded from ground. Then the MIDI file is processed on-board using a vocal synthesizer. Finally, the processed music is sent back to Earth using UHF antenna as voice FM data. "

Isn't music transmission prohibited in the United States amateur radio service?

Steve AI9IN