for me it shows me small little things in music i never would have picked up on if i didn't get stoned and listen to it again. sometimes it could be an obvious thing like a subtle synth line that just wasn't very high in the mix, but other times it can be something that makes the song just so much more amazing and i'll end up playing the song like 4 or 5 times in a row just jamming on that sound.
i imagine that weed would in fact enhance this musics enjoyability. for most music it makes me enjoy it less, and enjoy making music even less.
also the only time i don't enjoy making music while stoned is when i'm so high i can't play my instrument as well and i feel very stiff. other times i have a blast though and can just sit in my room for hours just messing around with effects and shit.