It's brother & sister against brother & sister in bitter fight over control of Frank Zappa's legacy

Inside a home recording studio known as the Utility Muffin Research Kitchen, where the late Frank Zappa composed and recorded some of his most adventurous works, his youngest son, Ahmet, reflects on his fathers legacy.
It is a rich musical heritage from one of rock n rolls most beloved figures, but one that has become entangled by a contentious family battle.
The Zappa Family Trust owns the rights to a massive trove of music and other creative output by the songwriter, filmmaker and producer more than 60 albums were released during Zappas lifetime and 40 posthumously. Like the intellectual property of many rock stars, the Zappa archives controlled by the trust are potentially worth at least tens of millions of dollars, according to one music insider.
Since the October 2015 death of Zappas wife, Gail, however, their children have become embroiled in a feud over control of the trust, which is millions of dollars in debt, pitting one brother and sister against another brother and sister. At issue is not just a celebrated artistic legacy, but even which of the children can perform using the Zappa name and profit from it.
http://www.latimes.com/projects/la-ca-ms-frank-zappa-legacy/