Chicago harmony group the Dells are not only one of the most influential of all R&B vocal groups, but also one of the longest lasting, with all the original members remaining together through five decades. Though they began in the doo-wop era (as the El-Rays), the Dells were influenced as much by gospel vocal groups as they were by pop and R&B. Their "Oh, What a Night" became a signature song of the era. Unlike most of their contemporaries, though, the Dells proved endlessly adaptable, altering their style to fit with musical evolution over the years. They were among the finest R&B groups in the '60s and '70s as well, scoring hits in each decade. In the '90s, there was a revival of interest in the group due to Robert Townsend's 1991 film THE FIVE HEARTBEATS, based on the Dells. For their enormous perseverance (and historic importance) the Dells were finally inducted into the Rock & Roll Hall of Fame in 2004.