Getting back to the topic of the OP, I always felt that as a singer he 'did the job', his singing being nowhere near his ability on guitar and harmonica.

On the subject of his feelings about 'the life of a traveling musician', here's the quote (from a site that's disappeared):

I would rather have a job where I could go home at night. I would have played music, of course. There's no doubt about that. Because I think you're born with music or whatever talent that comes out front in your blood, as the old-timers used to say, and you just couldn't help but pick the first time a guitar came along. You'd learn it. But it would have been a hobby. I'd like to have been a carpenter or an electrician or something kind of work like that, or a mechanic, if I could see. I can do rough carpenter work anyway.