Christine McVie, the singer, songwriter and keyboardist who became the biggest hit-maker for Fleetwood Mac, one of music’s most popular bands, died on Wednesday. She was 79.

Her family announced her death on Facebook. The statement said she died at a hospital but did not specify its location or give the cause of death. In June, McVie told Rolling Stone that she was in "quite bad health” and that she had endured debilitating problems with her back.

McVie’s commercial potency, which hit a high point in the 1970s and ’80s, was on full display on Fleetwood Mac’s "Greatest Hits” anthology, released in 1988, which sold 8 million copies: She either wrote or co-wrote half of its 16 tracks. Her tally doubled that of the next most prolific member of the band’s trio of singer-songwriters, Stevie Nicks. (The third, Lindsey Buckingham, scored three major Billboard chart-makers on that collection.)