Milton Babbitt seems to be the most recognized name when digging into the Columbia-Princeton era stuff. And is the only name that seems to generate some interest in actually releasing something - but not enough to get any momentum going. He composed 10 electronic pieces, one of which the synthesized part was unfinished, but notated, and a performing version was completed using performers on synthesizer to pick up where the tape ends.
Composition for Synthesizer
Vision and Prayer
Philomel
Ensembles for Synthesizer
Correspondences for string orchestra and synthesized tape
Occasional Variations
Reflections for piano and synthesized tape
Phonemena for soprano and synthesized tape
Concerti for violin, small orchestra, synthesized tape (unfinished tape)
Images for saxophonist and synthesized tape
Original 4 track tapes of the first 5 have been digitized. The rest, other than Concerti, last I knew, are in the possession of Milton's daughter. They were published by Edition-Peters, which has expressed no interest in the tapes, or putting any effort into preserving or digitizing them. As far as they're concerned the stereo materials they have are adequate.
Milton had no interest in moving into digital electronic music, and didn't move beyond composing on the RCA Mark II synthesizer. It was long rumored that he stopped composing on the synthesizer after it was vandalized from a break in and left unrepairable. This story has been found to be untrue. There have been other fun stories about the synthesizer - there were enough spare parts to build a 2nd one - last time it was turned on it caught fire. These are also untrue - there are a lot of spare tubes, and perhaps when powered on after being off for a long period of time it might let out a bit of smoke. The synthesizer just simply fell into disrepair from years of sitting unused. It could theoretically be brought back into use - but there's no interest or practical reason. I don't know if it's happened yet or still being talked about, but it seems there are plans to eventually remove it from the office it sits in, and display it in a case somewhere.
But - on the topic of Columbia-Princeton - another piece on the Finnadar album, Alice Shields Farewell to a Hill, has recently had it's tape digitized and has been performed. Alice has expressed interest on facebook in finding a way to release it, but she isn't sure how. People have mentioned things like atmos streaming and blu-ray.
