Jimi Hendrix (27), Kurt Cobain (27), and Tony Iommi (not in 27 club but co-founded Black Sabbath) are all rock guitarists associated with heavy/hard rock. Steve Vai is the outlier - a virtuoso guitarist known for instrumental rock and still alive, while Hendrix and Cobain died at 27 (the '27 club'). The pattern is either '27 club' or 'died young'.