"... a couple of gigs to help out some non-profit organizations ..."

If he's getting paid, he's helping Tom Lewis, too.

If he's not getting paid, which I assume is the case, shouldn't it be classed as a "personal interest" or "hobby" visit, and not need a work visa (let's ignore a few CD sales along the way, because they are probably for cash)?

$320 might seem a bit steep, but it looks like another one of those occasions where the honest person is paying for the extensive checking etc they have to do on the crooks.