I think everyone here has seen a performance by a band or artist that had a singer who simply plays off feel live. They can't sing like they do on an album. Deftones comes to mind right off the bat with a song like 'Digital Bath'. Nowhere close to the high notes in that one live.
If he wasn't tuned in the studio, it must have been a gooooood day. I love Chino and the band (my fav records are Deftones, love em to death), but live he can't sing some of the stuff he has on cd.
Point is.... don't be afraid to tune it if you're being paid to make the band sound good. If you are being paid per hour, then ya let him pay you to practice while you watch
This is getting away from the OP, since the singer is him haha
So to make yourself better, tune it up. Or practice. One of the two will need to be done!