60s US band, with the annoying "y", like The Byrds and The Turtles (Tyrtles). Managed by Brian Epstein, they had one big hit with "Red Rubber Ball", a piece of proto-bubblegum co-written by Paul Simon. The B-side (IIRC) "How Can I Leave Her?" was a cool folk-rock ballad. After the band's slow demise, the lead singers, Tom Dawes and Don Dannemann, went into commercials; you may never have heard The Cyrkle, but you have probably heard one of their advertising jingles.