Yessongs: 40 Years On

Christopher Russell Edward "Chris" Squire (born 4 March 1948), is an English musician, known as the bass guitarist and backing vocalist for the progressive rock group Yes. He is the only member of the group to appear on every album. Description above from the Wikipedia article Chris Squire, licensed under CC-BY-SA, full list of contributors on Wikipedia.

Stephen James "Steve" Howe (born 8 April 1947 in Holloway, North London, England) is an English guitarist, known for his work with the progressive rock group Yes. He has also been a member of The Syndicate, Bodast, Tomorrow, Asia and GTR, as well as having released 17 solo albums as of September 2009. Description above from the Wikipedia article Steve Howe (guitarist), licensed under CC-BY-SA, full list of contributors on Wikipedia.