Tool, Cog, The Butterfly Effect, Birds of Tokyo; all bands that spring to mind when you think about progressive rock, but they are the modern purveyors of the genre.
Kicking it all off a mere 43 years ago were English rockers Yes.
The band's bassist Chris Squire speaks to Pulse ahead of Byron Bay's Bluesfest.
Squire is the only member of the band, which has had 17 line-up changes in its history, to feature on every studio album.
"I think that's more by default than design," Squire says.
"People came and went over the years. Maybe that's why we've stayed together for so long because we've had so many changes. Personally I've enjoyed it. It's like a series of marriages."
His love of playing live keeps Squire going on the tour circuit.
"It's not really one of those professions where you have to retire," he says. "It's something you can do until you drop dead. Hopefully that's what I'm going to do anyway."
Yes released their first album in a decade last year, Fly From Here, but the time flew by for Squire who says it was more a matter of logistics than anything else.
"We released Magnification in 2001 and spent two or three years touring around the world with that album," Squire says. "We took some time off in 2004 and it was during that time Jon (Anderson, founding member and vocalist) was having respiratory problems."
The band went on hiatus while Anderson was getting treatment.
"When he was fit enough and we were about to head out on tour he had another attack," Squire tells Pulse.
This is why in 2009 Benoit David came on board. David had been the frontman in a Yes cover band in Montreal, Close To The Edge, which came to the attention of Squire when a friend showed him a clip on the internet.
"I thought it was Yes," Squire says. "Not just Benoit though, the whole band looked and sounded like us. So at that time I made a note of it and when we were looking for a singer I made contact with him."
Despite originally thinking his mates were playing a trick on him David was keen to come onboard.
Yes hasn't been Squire's only project. In the late '70s when the band were on a break (they'd broken up ... temporarily), Squire was working with Yes drummer Alan White and Led Zeppelin's Jimmy Page on what was to be called XYZ (X Yes and Zeppelin).
But nothing ever came of it.
"Yes were on a break at the end of the '70s and Jimmy was upset because (John) Bonham had just died, and he had died in his (Jimmy's) house which made it worse, and he wanted something to do. We lived not far from one another so he'd come around and play. Robert Plant was lined up to come and sing but it was all too early after Bonham's death.
"We did a bunch of demos and that was that."
There's no plans to take it further either; Squire says the demos are out there but he's too busy with Yes and another project Squackett (with Steve Hackett from Genesis) to worry about it.
Yes play Bluesfest at Tyagarah Tea Tree Farm on Monday, April 9. For the full line-up and ticketing info head to www.bluesfest.com.au