Marc Francis Costanzo (born August 1, 1972) is a Canadian singer, musician, music publishing executive and the co-lead vocalist of the alternative rock group Len. Costanzo and his older sister, Sharon Costanzo, formed Len in 1991, although the group has featured a revolving lineup of touring and studio musicians since its formation. In 1999, they released their third album, You Can't Stop the Bum Rush, which went platinum in the US and featured the platinum-selling single "Steal My Sunshine".
