The first example coming to mind is Abba of course. Besides that I can think of Fleetwood Mac.
― Ich bin kein Berliner (alex in mainhattan), Saturday, 27 October 2018 20:16 (six years ago)
I believe there were various permutations of the Mamas and the Papas at any given time.
― clemenza, Saturday, 27 October 2018 20:22 (six years ago)
I think Heart qualifies, at some point? My memory is that both Wilson sisters had inter-band flings
― Οὖτις, Saturday, 27 October 2018 20:28 (six years ago)
the original steeleye span lineup - gay & terry woods and tim hart &maddy prior
― velko, Saturday, 27 October 2018 20:35 (six years ago)
Long Blondes.
― Real Compton City G, Saturday, 27 October 2018 20:39 (six years ago)
the beatles
― la bébé du nom-nom (bizarro gazzara), Saturday, 27 October 2018 20:50 (six years ago)
Oasis
― the Warnock of Clodhop Mountain (Noodle Vague), Saturday, 27 October 2018 20:57 (six years ago)
― velko, Saturday, October 27, 2018 9:35 PM (fifty-one minutes ago) Bookmark Flag Post Permalink
Which was one of the main reasons that initial line up didn't last, the couples didn't get along very well.
― Stevolende, Saturday, 27 October 2018 21:27 (six years ago)
The Go-Betweens IIRC
― that's not my post, Saturday, 27 October 2018 23:05 (six years ago)