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