If I recall right his toupee came off on his way to the stage in the Norway Show. This required the band to play repeating riffs waiting for him to arrive on stage.

This is noticeable in the video of the concert.

I think there is another spot in the book about a hair dyeing malfunction.

You have to commend whoever made and fitted the toupee for excellent work. In the video of the concert you can see where Jim's hair was thin along the sides as well.

I think the best comparison is with Bing Crosby's hair piece and voice. Like Jim, both superb.

I have often wondered if God gave "male pattern baldness sufferers" great voices.

Quite a few out there.