The appeal was granted because of the Music Modernization Act, which makes these tracks eligible for digital performance royalties.
When the Flo & Eddie led lawsuit began in 2013, there was no federal law protecting streaming of music recorded prior to 1972. But the courts ruled that Pandora had violated laws in several states including California. Last week the appellate court ruled that the MMA preempts state-based claims if Pandora pays the royalties.
"The panel of appellate judges write they can't answer whether the MMA applies to and preempts Flo & Eddie's claims without a factual record about Pandora's compliance," according to The Hollywood Reporter. "But the Ninth Circuit sees fit to revive Pandora's attempt to strike the lawsuit and sets up the company's potential escape from the class action altogether upon remand."