Winterland 4/15/70 additional personnel

[Jim Powell]

Title: Winterland 4/15/70 additional personnel

We played the Winterland 4/15/70 That's It For The Other One last night at Ashkenaz Dead Night and, through that magnificent spearker system, it was obvious that the 5 minute jam following the first drums includes additional personnel.  A conga player joins during the first drums and in the 5-minute jam following there is a third guitarist (playing rhythm) and someone on keyboards (not Pigpen).  The jam itself sounds like a Santana riff so we were wondering if the additional musicians could be from Santana's band  --  Neil Schon on guiter & Greg Rollins on the keys?  Another guess for the person on keyboards would be Merl Saunders.  Jefferson Airplane was also on this bill; I don't know if anyone else was.  Comments?