No roster of durable rock veterans would be complete without Ann and Nancy Wilson, the sisters who have fronted the band Heart for nearly forty years. The sisters may not have founded the band, but they quickly became its public face, and Ann's smoking vocals defined its sound, even as its musical format shifted with changing times. Their performing style and their song-writing talents provided definitive proof, as Janis Joplin had before them and Chrissie Hynde would shortly join them in doing, that a woman could rock as hard, as dirty and as unreservedly as any man. They sang about losing their virginity, having one-night stands and raising children on their own without apology, and Ann's tough delivery brought to the lyrics a distinctive mixture of relish and regret that made the songs memorably ambivalent. But they could also write delicate ballads, which Nancy often sang. One of their biggest hits remains 1978's gentle duet, "Dog and Butterfly".