We saw the [surviving-and-still-talking-to-each-other members of the] Beach Boys a few years ago. There were young guys filling in for the missing members, and each of the survivors playing an instrument had a young double standing behind him. I found it amusing and honest when Mike Love told the audience "We recruit the musicians from tribute bands. They already know the songs!"saw them in concert at that same time.
At a different concert we saw an old 1960's group that had a different take on the question of "is this the real band, or a tribute band with rights to the trademark?" (Wish I could remember who -- maybe Canned Heat?) The band leader somewhat angrily noted that this was the real band, since "We had 37 different mebers during the 1960's and 70's and nobody complained then."