This video, via David Baron, captures a synth jam created with a vintage ARP 2500 modular synthesizer.
“Created entirely with the Arp 2500 Modular Synthesizer. A very rare synthesizer that was the chief competitor to Moog during the late 60s and early 70s.
Most of them were sold to rock stars (Pete Townshend) or universities. A large system was used to communicate with the aliens in Close Encounters of the Third Kind.”