William Basinski recorded this music during his time living in San Francisco, when he presumably visited Clocktower Beach. Considering that Basinski once created On Time Out Of Time—music in tribute to quantum entanglement and the theories of Einstein and Rosen, and Einstein, Rosen, and Podolsky, using source recordings of the 1.3 billion year old sounds of two distant massive black holes—undoubtedly the subject matter of The Clocktower at the Beach is one of his more straightforward creations. Fair enough, it is one of his earliest drone pieces, yet his methodology is as intriguing as anything he's done, and (most important of all) the music is a memorable journey into the sadness of things. Back to "mono no aware," then.
About that methodology: it seems that Basinski recorded the night shift at a sausage factory on a battery operated portable cassette player, then made this music from that source material chiefly using a Norelco Continental four speed reel to reel tape recorder. Looping and speed tampering is all very well on paper, but thankfully Basinski's ear is such that there is not the slightest trace of anything horrible, gimmicky, nonsensical, or even dull. Broken 1950s televisions, scavenged from the streets by James Elaine, were also used, I'm unsure exactly how but presumably as another sound source.