Good question!
Here's a little background before my question (in case you're not familiar with the musician who the question regards). Sorry if it's a bit long-winded (or if you're already familiar with him), but I have the utmost respect for the man and figured I'd ramble for a minute:
One of my favorite guitarists (and vocalists for that matter), Warren Haynes, started playing for the Allman Brothers in 1989, forming his side project, Gov't Mule, with Allman bassist Allen Woody in '94, and then left the Allmans in '97 with Woody to pursue Gov't Mule full time. In '99, he started splitting time between Mule and Phil & Friends (one of Grateful Dead bassist Phil Lesh's post-Dead groups).
After Woody's death in August of 2000, Warren took a few weeks off and then, after organizing a benefit concert in Woody's honor with the Allmans, the Black Crowes, Phil & Friends, and Gov't Mule (with bassists from those bands and also a couple of guests taking over bass duties for Mule), immediately jumped back on the road with Phil & Friends and continued playing through the end of the year with them, with Mule drummer Matt Abts for a few acoustic duo dates, and at a few other various benefit shows with Mule with more guest bassists filling in.
In 2001, he jumped back out on the road with Phil in February, rejoined the Allmans on the road in mid-March, and started touring with Mule at the end of March. He toured relentlessly with all three bands through September '02, when he left Phil & Friends. Since then, he's been splitting time with "only" two full time jobs with the Allmans and Mule, popping up for various solo, guest, and benefit appearances here and there.
So, on to the question (finally, I know):
Warren is obviously a blue collar musician who loves to work and can do his job well (as evidenced by his ability to master the enormous back catalog of music by the Allmans and the Dead, which is a definite necessity since they don't come out just playing a "greatest hits" concert every show, instead, switching up setlists every night). Before he started playing with the Allmans in '89, Warren got his start playing for a blue collar country musician from '80 to '84. Who was he?