What began as an idea for Built To Spill, Modest Mouse and Love As Laughter to record a collaborative album covering each other's songs has now morphed into something else entirely.

Built To Spill frontman Doug Martsch says when Modest Mouse's Isaac Brock approached him last summer, he was up for the covers concept, but when the two talked again months later, it didn't sound quite as enticing.

"We talked a little bit about maybe just going to a studio and having some sort of idea or a theme," he tells Billboard.com. "But basically instead of doing that, how about we rent some studio time, all of us converge and just f*ck around? We'd switch instruments and collaborate."

The only issue now will be to find time to actually carry the plan out. "I'm super busy and I bet Isaac is double super busy," Martsch says. "But I'm open to do it some day."

As previously reported, Built To Spill is touring this fall and performing its 1997 album "Perfect From Now On" in its entirety. The group will release its next Warner Bros. studio album early next year.

Modest Mouse just finished touring with R.E.M. and will have a new EP out before the end of the year via Epic. Love As Laughter's new album, "Holy," was released June 24 on Brock's Glacial Pace imprint.