The author wrote a 'quartet' of novels about the same character.
He is a member of a jazz 'quartet'.
a string 'quartet' by Beethoven
(..) Fishman, Chen, Chaudury and McNair aren't fielding a team in the university Physics Bowl this year. You're kidding. Why not? They formed a barbershop quartet and got a gig playing Knott's Berry Farm. So, in your world, you're like the cool guys. Recognize. (..)2008 TvShow: The Big Bang Theory Title: The Bat Jar Conjecture Season: 1 Episode 13