Is it normal that i sing the instrumentals in a song?

I sometimes sing along to electric lead guitar parts with that sort of nasally 'nyow nyow nyooowwww' noise.

I always sing to the instrumentals. If one of my friends is playing a song that I have no idea what the lyrics are, I'll either do an "ooh" or an "oh" in the background with the instruments. Blending. So much fun!

It's normal. Lots of people do it, like singing dubstep. BOO BWAGH BZ BZ DREOOUGGHHH etc.

You'd like acappella. You're already doing it.

if im ridin round with my dawg i changes the lyrics to suit him

barkdida bark dabork dabork squeaky squeaky sniffy sniffy bark dabork dabork woof

It can be hella fun, don't feel bad ㅋㅋㅋ

I do it with guitar riffs too

It's called scat when jazz singers do it