Breaking up is hard to do. But for Jason Isbell, former guitarist and songwriter for Southern rockers the Drive-By Truckers, splitting with his old bandmates had an upside: his long-pending solo caree

Breaking up is hard to do. But for Jason Isbell, former guitarist and songwriter for Southern rockers the Drive-By Truckers, splitting with his old bandmates had an upside: his long-pending solo career was finally on the fast track.

Isbell started writing for a solo album around four years ago. Although he didn't initially set out with a side project in mind, he says a batch of songs came together that just didn't feel like Drive-By Truckers material. "I was writing most of these songs on piano, which I hadn't done for Truckers songs, and the arrangements I was hearing in my head called for different instrumentation than we had in the band."

Isbell plugged away, but slowly. "It was a juggling act," he says. "We were touring a lot, staying really busy on the road, so I didn't have a whole lot of time. It's also hard to get in the right mindset on the road; your main concerns are staying showered, having clean clothes and being rested up for the next show."

Beyond that, Isbell wanted to give proper attention to promoting his solo debut once it was ready and his obligations to the Truckers meant setting up a tour of his own was repeatedly put on hold. "I really liked to tour, but I didn't have time to go out and get behind this in the way I wanted to, and that added to the delay."

Isbell had imagined "Sirens of the Ditch," which debuted at No. 10 on the Top Heatseekers chart, would be a companion piece to his work in the Truckers, hitting shelves when he finally had a chance to take a short break from the band. But things turned out otherwise when he and his bandmates decided to cut ties.

"It wasn't a complete surprise," Isbell says. "It was definitely something we'd been discussing, and we finally came to the decision that we didn't want to keep doing things the same way, that it wasn't as fun as it should be."

Jay Woods of New West Records, home to both the Truckers and Isbell's solo project, adds, "Maybe Jason didn't expect the timing to turn out as it did, but he really wanted to do his thing and now he can do it full-time. I think the fact that they still talk and turn up to each other's gigs shows they have a lot of respect for each other. It seems like everyone agreed it was just time go their separate ways."

For Isbell, the silver lining is the motivation and freedom he now has to promote "Sirens." He says having the solo album already in the can made the breakup "easier. It gave me something to transition into and I realize now how impossible it would have been to do both things at once -- at least properly. I'm putting all my energy into this, and I would have felt like I was short-changing myself had I still been in the band."

Isbell already has dates booked through the end of year, touring the U.S. through November and then heading overseas. And he hopes to do some new recording in the first third of 2008.

"Considering I've been working on 'Sirens' for so long, it's been a while since I've had a chance to go into the studio."

Woods says Isbell is a "dream to work with. He understands what it takes to do well and he's always ready to go out and do the work. And he made a beautiful record."