we had 2way radio and am-fm radio dating back to about 1980 in our busses..
our schools in 1986 bought 2 Bluebird / IHC diesels (their first diesels) with radios and A/C... then in 87 right before I graduated they bought a bunch of carpenter IHC diesels.. all had radios..
well provisions for radios.. the speakers and the PA amps were there.. the drivers had to put the radios in.. and all of them did.. it was a known fact when the kids had music on they were much more behaved... as long as the driver didnt play something like classical or the elevator station... the local medium rock station worked wonders..
most of the kids hated the A/C (I think i was the only one on the bus who liked it.. (and the driver).. most of the kids didnt like having to ride with the windows closed..
-Christopher