||Not listed in DeadBase XI. The tapes circulating with this date are from a "Heartbeats" show, without Bobby and Pigpen. (1) with Harvey Mandel (and George Chambers?). This jam has previously circulated as "Set 3" of 12/16/68, but Bill Gadsden says that it's "with Harvey Mandel from 12/24/68". From the San Francisco Chronicle newspaper of Monday December 23, 1968 pg 35: "At The Matrix tonight and tomorrow night: Jerry Garcia, Jack Casady, open end jam, no door charge" and elsewhere on the same page under the heading "OPENING tODAY": "ROCK CLUB - Jam Session with Jerry Garcia, Jack Cassady and others, from 9:30 p.m., The Matrix, 3138 Fillmore. Free." on page 26 of issue #34 (Summer 1996) of Dupree's Diamond News, Dick Latvala stated in an interview "There are tapes of 12/16/68 marked Hartbeats at The Matrix, but I don't know if that's really accurate. You know [David] Crosby was playing with them quite a lot that month." He makes no other mention of 12/68 Matrix tapes in that article, but he has stated on another occasion that the tapes in the vault of 12/24/68 are labeled as Garcia jamming with the Harvey Mandel Band.