Gail Zappa: Frank Zappa's wife, muse and manager who ferociously protected his musical legacy

From doo-wop to musique concrète, via assorted varieties of jazz and rock, Frank Zappa – guitarist, songwriter, composer – was perhaps the most innovative and stylistically daring musician of his generation. Underpinning his relentless quest to cross artistic boundaries was Gail, his wife, manager, muse, amanuensis – and, following his death in 1993, the zealous guardian of his musical legacy.

The daughter of a US Navy nuclear weapons researcher, she grew up in Hollywood; Jim Morrison was a childhood friend. She spent time in London when her father was posted to Britain in 1959, and modelled for David Bailey and Terence Donovan. She studied at the Fashion Institute of Technology in New York, then returned to Los Angeles. She met Kim Fowley, and recorded with him as Bunny and Bear.

She met Zappa in 1966 when she was working as a secretary at the Whisky a Go Go nightclub on Sunset Strip, and they married the following year when she was pregnant with their daughter, Moon Unit. They would have three more children, Dweezil, Ahmet and Diva.

On her husband's behalf – she described him as “the HG Wells of rock'n'roll” – she fought record companies and set up the Zappa and Barkin Pumpkin labels, alongside a mail-order business. Shortly before he died of cancer, Zappa told her to “sell everything, get out of the music business and go get a house at the beach.” She ignored him and set up the Zappa Family Trust, releasing 38 hitherto unheard albums that Frank had stored in a bunker beneath their home in Laurel Canyon.

If she had been a zealous protector of her husband's interests while he was alive, she became even more so after his death, defending his copyright and controlling the exploitation of his image. In 2008, she sued the Zappanale Festival in Bad Doberan in Germany, demanding that they change the name, take down posters which depicted a moustache similar to Frank's and remove the statue of him in the town centre. A court decided that the Trust had not exercised their trademarks in Germany for more than five years, and that the offending moustache was sufficiently different from Frank's.

Shortly before she died of lung cancer, she announced that the bottom of the Zappa archive had finally been reached and that Dance Me This would be Frank's final piece of work; it was his 100th album.

Adelaide Gail Sloatman, music manager: born Philadelphia 1 January 1945; married 1967 Frank Zappa (died 1993; two daughters, two sons); died Los Angeles 7 October 2015.