An era is ending for Tea Leaf Green just as another is starting. The San Francisco-based jam band's box set "Seeds," composed of the group's first three albums, dropped Tuesday.

Each of those discs -- 1999's eponymous release, 2001's "Midnight on the Reservoir" and 2003's "Living In Between" -- were self-released efforts that featured some serious jams.

"That's how things were then," vocalist-guitarist Josh Clark said while calling from Boston. "We jammed out, and everything was done by ourselves."

But last year, Tea Leaf Green signed with Surfdog Records. The independent label will release the group's forthcoming album, "Shadows at the Edge," by autumn.

The new album finds the group -- which includes keyboardist Trevor Garrod, bassist Reed Mathis and drummer Scott Rager -- morphing. The new material is tighter; the group eschewed extended jams in the studio.

"This time out we were much more focused when it came to recording," Clark said. "We avoided doing the jammy guitar solos and long piano breaks. We're growing up. ... We lived in that moment, but now we're thinking things out. We're less self-indulgent. We're about trimming the fat from our songs. Not that we're banking on it, but maybe we can get on the radio with the songs we've written and recorded. We realized that the studio is not the place to jam, at least for us."

That's why you can count on the group to go on extemporaneous runs when it performs on stage, including its Wednesday show at the Lincoln Theatre.

"Live is the place to jam," Clark said. "That's where you can take chances and stretch things out. We still do whatever we feel when we get up there on stage."

Clark is still laid-back when it comes to his approach to music. In fact, the charismatic songsmith is inspired by the sounds of the '60s and early '70s. It's the free-spirited manner of music-making during that bygone era that appeals to him.

"I love that period. Right now I'm watching an Elton John DVD released by the BBC during the early '70s. It's amazing. I find music for the most part being made today being overly earnest. I prefer the whimsical way musicians from the '60s went at it. I think you'll put us in the whimsical category when you hear our new songs."

The band will preview a few cuts from the disc on its spring tour.

"We'll just do a couple of the new ones," Clark said. "We're going to save a few of the songs for when we come back when we tour after the album comes out. We always did it the opposite way before. We would test out all the songs, but as you'll see, we've changed a lot as a band.

"But it's good to do things differently. If you stay together long enough, you're most likely going to change, which is a healthy thing."