With legendary rocker Lou Reed in the audience at U2's show in Oakland, Calif., earlier this week, drummer Larry Mullen Jr. took a rare turn on the mic for the chorus of Reed's 'Perfect Day.'

While the stickman's singing would likely have earned him a bewildered look from Steven Tyler and the rest of the judges on 'American Idol,' it was a unique treat for those in attendance.

Bono followed up by letting the crowd know that the former Velvet Underground frontman was in attendance, saying, 'the great man has walked amongst us." He later threw in a bit of Reed's 'Dirty Blvd.' into the song 'Vertigo.'

Before the Reed tribute, guitarist the Edge told the concertgoers that select members of U2 had dinner with the guys in the Bay Area bands Metallica and Green Day. He said they all "discussed the possibility of the three bands creating their own festival and touring."

Meanwhile, the Edge and bassist Adam Clayton chew over the future of U2 in a new Rolling Stone feature. In it, the Edge says the band's next album probably won't be out until fall of 2012, while Clayton admits that his bandmates' involvement in the 'Spider-Man' musical has cost them valuable studio time.

Watch Larry Mullen Jr. Pay Tribute to Lou Reed at U2's Show in Oakland