Sigma 6 was a rhythm and blues band formed in 1964 by Roger Waters while he was studying architecture at a college in Cambridge.

The band initially consisted of the following members:

• Roger Waters - lead guitar
• Nick Mason - drums
• Richard Wright - keyboards
• Clive Metcalfe - bass
• Juliette Gale - vocals

Bob Klose subsequently replaced Metcalfe shortly thereafter.

The band went through a number of name changes including The Architectural Abdabs and The Screaming Abdabs but were unable to keep band members and the group broke up in 1965.

Soon after the breakup, Waters, Wright, and Mason would join Syd Barrett to form The Pink Floyd Sound.

Reference

• Pink Floyd Biography

Nb. The Screamin' Ab Dabs was also the name of an early 1980s rhythm and blues band from South East Essex fronted by Alison Moyet