If I could turn off hearing other people's mount music, then OK, I guess. If not, then a big fat NO.
I'd imagine that in mount-capable zones, it would turn into a sort of online version of student stereo wars, especially if Epic+ flooded the entire zone.
Unless turning on your mount music also raised your PvP flag with a two-hours-connect-time cooldown...
Overall, I'd say no. It would be a negative thing. Mount music that only the rider can hear, OK, but not in broadcast mode, thanks.
Now f2p 60 Xadaganian summy with 60/60/60 tailor/weaponsmith/alchemist, bleah gear, 555/555 runes
Now p2p 28 Xadaganian avenger with 20 weaponsmith
I'm on an extended break from Allods at the moment, but I'm lurking here to keep up with what's happening. From the looks of things in 5.0.02, I'm better off where I am.