Is this a thing that any of you guys feel like you're affected by?
I've found that I really can't hum (let along sing) one note to save my life. If you ask me what a G is, I can play one for you, but I won't be able to imagine it beforehand, or produce it with my mouth until I get an audial cue. I can barely do scales in my head (I always seem to miss a step), and if I try an arpeggio, I might get it sort of right, but my starting note will nearly always be flat somehow.
It gets more embarrassing when I think I'm singing the right thing, but then when I listen back to it I'm sometimes out by an entire semitone.
I wonder if there's a way I can teach my brain how to distinguish certain notes so I can always be sure of what I'm hearing. Like... going to bed with a pair of earphones and listening to a track of various instruments all playing one note while I sleep, heh. It should be easier once I'm past that point to actually play/sing the correct notes over the top of whatever I have playing at the time.