I hear music and sounds in my dreams somewhat often, usually ambiance.
Usually i dont really remember my dreams, but i can hear music before dreaming, especially if i didnt slept for about 24 hours or more.
This shit is spooky as fuck
The one time in my life I have heard music in my dream was the song FIRST DAWN, AMBER WIND by Alstroemeria Records. It was 'playing' so loud that I think it caused me to wake up, although the room was completely silent when I did.
I love my dream music, though it is rare. I often hear synth or rock music and it's always the most bestest thing that ever resonated in my brain. Once I wake up however, it's incredibly hard to recall even the basic melody or instrumentation.
I sometimes hear music from whatever video game i played before i go to bed. I've experimented with this by playing yume nikki, earthbound, LSD dream emulator, etc. one experience i had was when i was in a neon city similar to moonside from earthbound and i could hear moonside swing faintly playing. it was awesome. of course, this probably means i play WAY too much video games…
Only one time that I can remember, it was a song "created" by me. Nothing interesting, I was dreaming that I was streaming music on youtube but after I woke up I realised that the song doesn't actually exist.
I remember hearing Libera me from hell with muffled, untuned and roughed out instruments once. I don't remember in what context and backdrop it was in though. I hear music pretty often in my dreams, often ambient scores or the music of the devil.