Though I'm a bass player, I'm not a musician. I can appreciate music and I can even imitate some good musicians on my bass, but I have no musical talent of my own. I've only ever composed one tune of my own in my entire life and that was like getting a root canal to get it done and sounding right.
Otherwise, there is literally no music of my own in my head at all, ever. Only the music someone else has made and that I've learned to play; otherwise upstairs, it's dead silence.
I call it the "Salieri syndrome".
In fact that's what finally made me decide to end my career as a gigging, active bassist. There's just no point to it because I just don't have that creativity that you need to really be musical on the bass. I can play if it's someone else's part, but I've never been able to create music myself.
The other, but more minor, problem is my hearing, which is now too damaged even to play other people's music in a live setting. Ironically, above a certain volume, low frequencies all sound the same as a hard distorted "bzzzzzzzz" lol. It's very strange and only at high volumes. At low volumes it's fine, but I could never gig unless it's just a really quiet setting with electronic drums, etc.
L