Sonja Kristina (born 14 April 1949, Brentwood, Essex, England) is a British songwriter, musician and actor, best known for starring in the seminal 1960s musical, Hair, and for being the female lead vocalist of the 1970s progressive rock band, Curved Air.Sonja is also an experienced voice coach. She was the Rock, Jazz and Musical Theatre tutor for Performing Arts Students at Middlesex University from 1991 to 1999.