This could represent a challenge but I can offer from the 70s: Supertramp
Roger Hodgson
Rick Davies
John Anthony Helliwell
Bob C Benberg
Dougie Thomson
Well it is a bit morbid however it is a fact.
My favourite band are Sparks and officially there are only two members, The Mael brothers, Ron and Russell, both in their late seventies.
In the event of either of their passing, I don’t know what I’ll do as they have been a part of my life since I was seven years old (1974)
However anyone that’s seen them recently will agree they are both fit and healthy and very clean living so they’ll probably outlive me.
A sad tale was that of the drummer, Dinky Diamond who was on two of their biggest selling albums (Propaganda and Kimono My House) He had a long running dispute with a couple of noisy chavvy neighbours which finally pushed him over the edge. The local authority did nothing (I think this was out Aldershot way, somewhere like that) One night he got pissed, went home and hung himself, incredibly sad.