A look at the biggest-selling singles of 1971, the best pop videos, the artists who appeared in them and the stories behind the songs - from Shirley Bassey and Diana Ross to Rod Stewart and Slade. Plus, interviews with Dana, Suzi Quatro, Merrill Osmond, Tito Jackson and others. Tony Christie and Judy Collins recall their chart success, and Middle of the Road look back on their biggest year.