[Maceman]

Also, how have radio stations been able to legally play music for free over the air waves for the past 90 or so years?

They do pay royalties for the songs they play.

[TomGuy]

They do pay royalties for the songs they play.

There was a time (may still happen) when musicians would actually go from one smalltown radio station to the next and literally beg them to play the artist's recording on-air.

==

I do recall several years ago some of the record companies trying to get retro-royalties from internet radio stations. Many of those internet radio stations just relocated their IPs to foreign countries.

[a fool in paradise]

They do pay royalties for the songs they play.

Originally the Supreme Court decided that they didn't (just as someone making a recording of a song didn't have to pay the publisher of the sheet music).

But the musicians unions were losing out on radio gigs when stations played records. Stations still pay into a fund to give live musicians paying gigs.