Tim Hart (9 January 1948 - 24 December 2009) was an English folk singer and multi-‎instrumentalist, best known as a founding member of electric folk band, Steeleye Span.‎

http://en.wikipedia.org/wiki/Tim_Hart

Madeleine E. "Maddy" Prior, (born 14 August 1947) is an English folk singer, best known as the ‎lead vocalist of Steeleye Span.‎

http://en.wikipedia.org/wiki/Maddy_Prior