Compare the later IBM 7094, famously used to sing Daisy Bell, as darkly referenced in 2001: A Space Odyssey.

I can't find the longer demo recording. Right before the song, they did the soliloquy from Hamlet. "To be, or not to be - that is the question. Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune, or to take arms against a sea of troubles, and by opposing, end them. To die, to sleep..." And then pointedly not suggesting that a computer can dream.

Very neat