"Bear Melt" is an improvised musical piece and as such unique. But a long improvisation like this was often done by the Airplane in their shows. If you check out bootlegs of Jefferson Airplane these improvisations are referred to as "Thing" or just "Jam", some of which do sound more or less like "Bear Melt" . But what makes the recording on BIPLH different is that Grace is singing along. All other improvisations known to me are instrumentals. Whether Grace made up the lyrics right there on the spot or whether she tried to sing along before is not known.
No video though. Very little footage of Jefferson Airplane exists. Maybe Wolfgang's Vault has a surprise for us.