Hey thanks a lot Dietmar! Glad you are enjoying the book. There are some altoists that are good rock players with a good rock sound, Edgar winters come to mind and older than that is one of the guys I mentioned in the Killer Blues book; Earl Bostic. But for the most part you will find most rock bands will have a tenor.
I played in Hannover a couple time and toured with a band called BB and the Blues Scacks from that area (Hildesheim) do you know of them?
Anyway good luck with your alto!
Johnny