What does harris attempts to sing comic songs tell us about him?

I've always felt that the fact that Harris attempts to sing comic songs speaks to his self-confidence......

"You have never heard Harris sing a comic song, or you would understand the service I had rendered to mankind. It is one of Harris’s fixed ideas that he can sing a comic song; the fixed idea, on the contrary, among those of Harris’s friends

who have heard him try, is that he can’t and never will be able to, and that he ought not to be allowed to try."