For Heart, this transition was compounded by the changing personnel in the band. While the Wilson sisters (Ann - vocals and Nancy - guitar) remained the constants, guitarist (and Nancy's longtime boyfriend) Roger Fisher left Heart in 1979.
Undeterred, Heart soldiered on, releasing the Bébé le Strange LP in 1980. This is a fascinating album, as the band's music is all over the place - to my ear, this sounds like a group working to rediscover what their sound is. In the midst of this experiment is a great straight-up rock song, "Even It Up," with a cool early video to boot. Particularly noteworthy are sailor Nancy (who seems to really like her Stratocasters), and the sax trio.
Bébé le Strange went gold and peaked at #5, while "Even It Up" reached #33. Heart's greatest hits album was released later in 1980, and marked the end of their first period of mainstream success. We suspect that most listeners and critics at the time would have viewed this as the likely end of the band. Improbably, Heart re-positioned themselves as a pop/hair band in the mid to late 1980s, ushering in a period of commercial success that was even greater than their 1970s heyday.
Heart has remained active for many years, but appears to be on hiatus as of this writing.