Tool / A Perfect Circle / Puscifer frontman Maynard James Keenan's birthday was back in April, but the prolific musician celebrated his 50th in grand fashion on May 10 and May 11. Maynard's 'Cinquanta' event was held at the Greek Theatre in Los Angeles and the guest of honor performed with both A Perfect Circle and Puscifer during the occasion.

Puscifer tore through a 14-song set both nights, delivering their brand of experimental and comedic rock with a few special surprises. A Perfect Circle guitarist Billy Howerdel stepped onstage to perform during 'Monsoons' on both nights, while Tool's powerhouse drummer Danny Carey sat in on the set's final four tracks on May 10, which included the Tool single 'Sober.' Tool bassist Justin Chancellor also hit the stage for 'Sober' (watch above). The second night's entertainment actually included Maynard's son Devo Keenan, who performed a cello solo before helping out on 'The Humbling River.'

Newly-reunited alt-rock act Failure performed at Keenan's birthday bash as well, jamming favorites such as 'Saturday Savior' and 'Heliotropic.' Failure also brought some invited guests onstage, including Maynard himself, who helped out with 'The Nurse Who Loved Me' and 'Solaris.' Billy Howerdel and Puscifer co-vocalist Carina Round also hit the stage for 'The Nurse Who Loved Me' before APC / Puscifer drummer Jeff Friedl jumped in for 'Wet Gravity.'

A Perfect Circle performed two sets for Maynard's birthday bash -- one on May 10 and another on May 11. The first set consisted of nine songs, celebrating the earlier years of the band. Along with tracks mostly taken from 'Mer de Noms' and 'Thirteenth Step,' the newest APC song, 'By and Down,' was used to close the night. Interestingly enough, A Perfect Circle's May 11 set was very similar to the previous day's, with only one 'eMOTIVe' track, 'Counting Bodies Like Sheep to the Rhythm of the War Drums' being performed during both nights.

Check out some footage from Maynard's 50th birthday celebration above and below!

A Perfect Circle, 'Counting Bodies Like Sheep to the Rhythm of the War Drums' (Live)

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