I would hear 'echoes' of the weekend's music playing in my head on Mondays, following LSD use at music festivals.
I have twice, after consuming psilocybe mushrooms, heard background noise (once with ocean waves, another time with electric fans) morph into some angelic symphony, as if the universe was playing music just for me.
The first time I had DMT, I felt this instantaneous surge of tryptamine terror coursing through me and instinctively stood up and tried to walk away from the situation. I moved through a mercurial slosh composed of metallic alien beetles crawling in a diagonal formation across my living room floor. My ability to see was now completely compromised, but I was able to follow the music inside my head, a symphony orchestra playing The Prodigy's Break & Enter. Several minutes later, I was upstairs, in the sanctuary of my bedroom, having been guided to safety by only faith, luck and the opening track from Music For The Jilted Generation.
Several mescaline adventures ago, I slipped into something of a waking dream, walking through neon lit streets of immense colour and graphic detail. I remember walking past a nightclub door and hearing, very clearly, the untz untz untz bass of the music playing within.
An early 90s documentary showing footage from a rave on new year's eve features a scene where a couple, still off their tits on MD after sunrise, continuing to dance to invisible music despite the sound system having been turned off some time earlier.
So yes, psychedelic drugs and music coming out of the aether - not an unreasonable phenomenon.