I've never really been much a fan of his work, but Kevin Kelly has posted an interesting email from Robert Rich discussing how he's been able to make a living as a "microcelebrity."
So let's look a bit at the finances. If I can make about $5-$10 per download or directly sold CD, and I sell 1000, I clear a maximum of $10,000 for that year's effort. That's not a living. Let's say, after 20 concerts I net about $10,000 for three to four months worth of full time effort. That's not a living.