Originally from Montreal, during the early part of his career, Greenspoon was a performer primarily on the acoustic music scene, travelling across Canada and the United States.
In 1978 he moved to Toronto to join Sylvia Tyson and The Great Speckled Bird, and later became a guitarist for many other prominent Canadian acts, such as Murray McLauchlan, Kate & Anna McGarrigle, and was also a member of the quirky mid 80's act, The Romaniacs.
Greenspoon played, as part of The Great Speckled Bird, for both seasons of Sylvia Tyson's CBC TV show Country In My Soul (1982-1983) and also played guitar for the entire 5 season run of the CBC Radio show Swinging On A Star (1989-1994) hosted by Murray McLauchlan which featured top acts from Canada and the US in an acoustic, live-to-tape, informal setting.
He was also the co-producer of the show Hot Ticket which showcased both Canadian and international acts in concert.
Greenspoon has produced over 50 albums mainly in Canada for Great Big Sea, Spirit of the West, Jane Bunnett, Ian Tyson, Willie P. Bennett, Joel Kroeker, Susan Crowe, The Paperboys, The Barra MacNeils, The Good Brothers, The Pukka Orchestra and Victoria Williams, among many others.