Spoof rock supergroup Spinal Tap want British comedian Ricky Gervais to join them on stage when they perform at this summer's (07) Live Earth concert. The band, created for 1984 rockumentary This Is Spinal Tap, are booked to appear at the Wembley extravaganza, which aims to raise awareness of climate change. Director Rob Reiner and the stars of the fictitious band, Christopher Guest, Michael MCKean and Harry Shearer want Gervais to join them. Gervais befriended Guest after shooting to fame with his own spoof documentary, The Office, and he subsequently made a guest appearance in Guest's 2006 film For Your Consideration. Reiner - who also played documentary maker Mart DeBergi in the film - reveals, "I'm hoping that Ricky Gervais is gonna be there. We're trying to convince him right now, but Marti DeBergi is definitely going to introduce Spinal Tap."