David St-Hubbins and Nigel Tufnel have been friends since they performed as children outside London's tube stations. Working under a succession of names, they eventually found success in 1967 as Spinal Tap. Within a year, their singles were climbing the charts. The band expanded and in 1983, armed with a new record label, they returned to America after an absence of six years. They were greeted by film director Marty Di Bergi - a Spinal Tap fan for sixteen years. This is the film he made of their tour into the American heartland.