In that scenario, you would have to have 100 accounts. It is possible to get licensed to do that (i inquired about it for an app i wanted to expand www.r3vl.com) but those music API services require a 6 digit sum of $$$ for commitment... so i moved on
quick edit, if those 100 speakers were simply ONLY broadcasting, you could get licensed as a radio, but if you want the ability to have others select songs, it is pricey
quick edit, if those 100 speakers were simply ONLY broadcasting, you could get licensed as a radio, but if you want the ability to have others select songs, it is pricey