4’33” or “any sounds may constitute music”

Yes, it does seem Reich knew about this effect well before Deutsch did, but maybe didn't realize it was something that could be given a classification of "audio illusion". And he's added the phase aspect to this piece as well, using the echo that he slows down and then speeds up through the piece. The vocal "phasing" part of this particular Reich piece gets very much into Deutsch's HI LO illusion, too.

I did a guitar version of his song Piano Phase on YouTube, and then followed up with 2 related pieces using a Guns and Roses theme and a Paganini arpeggio sequence to similar effect. I like how they begin just sounding like an echo, but as the echo gets spread out and distant, different melodies and rhythms emerge that just weren't there before. The repetition and pairing up with differing notes produces something that is definitely something unexpected.

Deutsch would probably be interested in that aspect as well.

Here's the guitar version of Piano Phase: https://youtu.be/9BG9hP6gqYc

And the G'n'R phase: https://youtu.be/PEaDItL1EJU

I thought I uploaded the Paganini one. I'll have to search it out and get it in my playlist.

EDIT: Found it. I just never made a video for the Paganini Phase: https://soundcloud.com/intruder-1/paganini-phase-steve-reich