They will travel time, space and style, gathered with the mission to save rock'n'roll.
Ever heard of Marvel Comics 'The Exiles'?
Exiles are a group of heroes from different dimensions, or realities, which have been removed from time and space in order to correct problems in various alternate worlds and divergent timelines in the Marvel Multiverse.
I removed rockers from different styles, and most importantly, their versions from distinct time periods, and put them together to imagine what kind of new kick-ass music they would deliver - each of them having the set of skills and creative potential of the time point they were removed from.
The mission these guys would have to accomplish? Save rock'n'roll.