An art rock supergroup whose members are closely associated with prog giants Yes, CIRCA: debuted in 2007 with the aptly named Circa: 2007. Initially comprised of Alan White (drums), Tony Kaye (Hammond, keyboards), Billy Sherwood (vocals, guitar), and guitarist Jimmy Haun, the band issued two more albums before coalescing around a lineup consisting of Sherwood, Kaye, drummer Scott Connor, and bassist Rick Tierney. CIRCA: released their fourth LP, Valley of the Windmill, in 2016.

Sherwood's affiliation with Yes dates back to his involvement with the late-'80s spin-off group Anderson Bruford Wakeman Howe, on which he and his former Lodgic bandmate, guitarist Jimmy Haun, did some session work. In the years that followed, both he and Haun became further involved with Yes and its various offshoots. Following a series of Yes-related projects in the mid-2000s, Sherwood and Kaye decided to form a proper band and recruited Haun and Yes drummer Alan White to form CIRCA:. They made their recording debut with Circa: 2007, supporting it with a handful of North American dates later that year. By late 2008, drummer Jay Schellen had replaced White, and this lineup delivered their follow-up, 2009's Circa: HQ. Another new project was formed later that year that included members of CIRCA: fronted by Toto singer Bobby Kimball. Under the name Yoso (a combination of Yes and Toto), they released their lone album in 2010. By the time Yoso had disbanded in 2011, Sherwood and Kaye remained as the only core members of the original CIRCA: lineup.

With new drummer Scott Connor and guitarist Johnny Bruhns, CIRCA: returned to the studio and delivered their third album, 2011's And So On. 2012 saw Sherwood switching to guitar with the arrival of new bassist Ricky Tierney, and this lineup recorded the 2013 concert album Live from Here, There Everywhere. After signing with Frontiers Records, CIRCA: released their fourth long-player, the intricate and proggy Valley of the Windmill in the summer of 2016. ~ Timothy Monger, Rovi