Donald Fagen is suing the estate of his bandmate, Walter Becker (who died in September), over the rights to and continued use of the Steely Dan name. From The Hollywood Reporter:

At the center of the lawsuit is a 1972 Buy/Sell Agreement signed by the original bandmembers when Steely Dan was incorporated. According to the complaint, which was filed Tuesday in L.A. County Superior Court, the contract provides that whenever a member of the group quits or dies Steely Dan purchases all of that members shares in the group.

"By the 2010s, Fagen and Becker were the only remaining shareholders and signatories to the Buy/Sell Agreement," writes attorney Louis "Skip" Miller in the complaint. "Four days after Becker’s death, on September 7, 2017, the Becker Defendants sent Fagen a letter stating that 'We wanted to put you on notice that the Buy/Sell Agreement dated as of October 31, 1972 is of no force or effect.'"

That letter sent by the Becker estate also sought to give Becker's widow 50% ownership of Steely Dan and to make her an officer of Steely Dan. Fagen also says that Becker's estate currently operate the Steely Dan website and refuse to give him access or him share control. He is also suing the band's management firm, claiming they've been withholding records.

Having toured as Steely Dan in October, Fagen is seeking $1 million in damages and is asking the court to make a declaratory judgment on the buy/sell agreement to say that he is the sole owner of the Steely Dan name.