James Aaron Diamond (28 September 1951 – 8 October 2015)[1] was a Scottish singer-songwriter, best known for his three top 5 hits: "I Won't Let You Down" (1982), as the lead singer of PhD; and his solo performances "I Should Have Known Better", a United Kingdom No.

[4] That line-up included bassist Chris Glen who went on to play with the Sensational Alex Harvey Band,[5] and Jim Lacey on lead guitar who later went on to join the Alan Bown Set.

Jade played many pub, club and university gigs in London in 1969, playing at Brunel University, West London College in Cricklewood, The Pied Bull in Islington, West Hampstead Country Club, another college in Virginia Water and many more in 1969.

They were soon signed up by Arista Records and released a début album, Bandit, which failed to reach the chart.

Bob Geldof praised Diamond for publicly encouraging fans to buy the Band Aid single instead of his own.

In the late 1990s, Diamond teamed up with saxophonist Chris "Snake" Davis, known for his work with soul outfit M People.

All proceeds from this album of soul music covers benefited the children's charity, Radio Clyde Cash for Kids.

The couple had two children; their son Lawrence is the keyboard player of the UK indie pop group Citizens!