Legendary rock band Aerosmith kicked off its long-awaited "Peace Out" farewell tour in Philadelphia on Saturday.

Aerosmith took the stage at the Wells Fargo Center, where they were joined by special guests The Black Crowes. 

The band played crowd-favorites such as "Back in the Saddle" and "Janie's Got a Gun," among other hits. 

It was the first show of their 39-stop tour, which they announced in May. 

"After 50 years, 10 world tours, and playing for over 100 million fans... It's time for one last go!" the band wrote on Instagram.

The five band members, which include frontman Steven Tyler and guitarists Joe Perry and Brad Whitford, are all in their 70s now. They got their start in 1970 in Boston and went on to reap international success and critical acclaim. The band has won the Grammy for Best Rock Performance by a Duo or Group four times — for 1991's "Janie's Got a Gun," 1994's "Livin' on the Edge," 1995's "Crazy" and 1999's "Pink."

In 2012, the band talked with Lara Logan on CBS News' "60 Minutes" about their tumultuous 40 years together. "I think my perfectionism and my busting everyone's chops is what got this band to where it is today," frontman Steven Tyler said. 

"There's no doubt about Steven's greatness. When you ask what makes the band great, I think that it's a combination of all of us. What that was right now, I can't tell you," drummer Joey Kramer said.

"I think a lot of it is [Tyler is] unbelievably competitive. You know he's competitive with us. With each member of the band," bassist Tom Hamilton said.

The band will close out the tour on January 26 in Montreal, Canada.