Guitarist Phil Collen talked about Def Leppard‘s reluctance to invite other musicians onstage to jam during live shows, telling All Things Considered during a recent interview (via Blabbermouth):
“Usually the songs are pretty complex. We’ve done a Creedence song once and brought Brian May out from Queen and Bon Jovi and Richie Sambora another time, that was pretty simple.
“Stuff like ‘Photograph’ and those songs are very specific and the harmonies and that, we don’t want someone messing them up. We traditionally don’t do that.
“Having said that, I just got off the G3 tour with Joe Satriani and John Petrucci and we would have a jam session every night, about half an hour and three songs and we’d invite guitar players. That was amazing, really fun.
“In Def Leppard, it’s a very different structure, if you like. We use backing vocals as an instrument and all of the sudden, you can’t just let anyone in on that. It’s going to change the dynamic.”