The Blues Brothers count, in my opinion. They didn’t just put a bunch of great session players together for the movie - the band was put together in 1976 with largely the same lineup as in the movie. They not only played on Saturday Night Live, but the entire band with Ayckroyd and Belushi played live gigs, including opening for The Grateful Dead two years before the movie was made.
Warning: Blues Brothers geekery ahead:
In 1978, two years before the movie, they released Briefcase Full of Blues, a live album that was truly outstanding. It went to #1 on the billboard album charts and had a big hit with ‘Soul Man’. Their movie sountrack also went to the top 40 and spawned another hit with ‘Gimme Some Lovin’.
Furthermore, the band stayed together after the movie, touring sometimes with Ackroyd and Jim Belushi, then with their own frontmen when Ackroyd and pals weren’t available. They collaborated with other musicians as the Blues Brothers Band.
In 2000 they again played the band in ‘Blues Brothers 2000’, a godawful movie with an excellent soundtrack. Then they went back out and toured again.
They are still touring today. The surviving members are ‘Blue Lou’ Marini, Tom Malone (who I don’t think is playing with them) and Steve Cropper. Donald “Duck” Dunn died in 2012, and Alan ‘Mister Fabulous’ Rubin died in 2011. Matt ‘Guitar’ Murphy died in 2018.
They have been together as a band with essentially the same lineup continuously from 1976 until today, except for replacing those that died. Of course being world-class musicians they have individually played with all sorts of other musicians as well.
They really were/are a supergroup:
Marini and Malone were members of Blood, Sweat and Tears.
Dunn and Crooper were part of the legendary Booker T. and the MGs. Cropper co-wrote Green Onions with Booker T, Sittin’ on the Dock of the Bay with Otis Redding and In the Midnight Hour with Wilson Pickett among other hits. Lennon and McCartney admired him so much they made plans to travel to Memphis to work with him, but it never happened.
Alan Rubin was a prodigy and trained at Julliard. His last performance before he died was with the Blues Brothers band in 2010.
Matt ‘Guitar’ Murphy was a Chicago blues legend who played in Howlin’ Wolf’s band, made two albums with Chuck Berry, and played with pretty much the who’s who of the Blues. And yet, he stayed a member of the Blues Brothers band for almost 30 years until he died. He was inducted into the Blues Hall of Fame in 2012.
If we were making a list of the most talented bands in history, they’d have real shot at #1.