After such a lengthy history with (and without) Aerosmith, Joe Perry knows a thing or two about keeping bands together. Sometimes, it's about more than the music you make, he says.

Case in point? Guns N' Roses, according to the guitar hero. As Aerosmith prepares to kick off summer dates with the band's former guitarist Slash on Thursday, Perry says he understands why Guns N' Roses' best-known lineup split -- and why they've stayed that way.

"It would be great for the original band to get back together," Perry tells USA Today, "but it takes more than great songs to keep a band going. Slash has done an amazing job on his own."

Slash was a co-founding member of Guns N' Roses in 1985, but was gone by '96. That era saw all of the band's other classic-era members leave too, with the exception of frontman Axl Rose. Slash has been recording and touring more recently with Myles Kennedy. Their next album, titled 'World On Fire,' is due in September.

Meanwhile, Perry himself was out of Aerosmith for nearly five years, beginning in the summer of 1979. Fellow guitarist Brad Whitford was also missing for much of 1981-84. Perry didn't appear on 1982's light-selling 'Rock in a Hard Place,' and Whitford made only a passing contribution.

Perry blames longevity for those kind of ups and downs. "Some of us were teenagers when we put this together," he says. "You can't keep five people who grew up together in a rock 'n' roll band and not have some turmoil. It's amazing we kept this thing going. ZZ Top is the only other band I know of still doing it this long with the original members."

(Then again, do we REALLY know who's behind those beards on any given day? They Texas trio could have had more lineup changes than Menudo, for all we know!)