A $500 reward is being offered to anyone who can provide a recording of the Grateful Dead’s March 17, 1970 impromptu show with the Buffalo Philharmonic Orchestra. 

The Buffalo News reports that it all began with a tweet on January 5 about the show and subsequent response from radio personality Michael Caputo, offering a reward for the show. “For tapers – the Dead fans who attended and lovingly taped every show – this recording is like Moby Dick, elusive and mythical because every expert from Owsley ‘Bear’ Stanley to David Lemieux says nobody taped that night,” Caputo said. “”Deadlist.com says the tape doesn’t exist and that normally means forget it. But I’m not buying it.”

Caputo noted that he’s “heard of this great white whale recording” for 40 years, even saying he believed he’s listened to the tape before. 

Not much about the show is known, as Setlists.net notes just three songs, “Dark Star,” “Drums” and “Turn On Your Lovelight” played that night along with a few reviews from those in attendance.