He's originally from South Africa, though I believe he's an official US citizen now. When Yes was re-forming during their mid-career shakeup in the early 80's, he was Steve Howe's replacement. He took the band in some interesting new directions, and wrote a lot of the music that we associate with Yes today. For instance, "Owner of a Lonely Heart" was something he brought to the band. I really enjoy both his solo work, and his work with Yes. His style and technique are amazing, and he's a great composer. He's among my all-time favorite guitarists.