Invisible Visionaries are producers and A&R men behind the scenes, whose careers made a difference.
If they had not been there, not only would many great records not have been made, but in some cases entire genres might not have emerged.
The series runs 10.00 pm each Wednesday for the first ten weeks of 2006 on BBC Radio 2.
Listen Again at http://www.bbc.co.uk/radio2/
choose 'Without Frontiers'