Steve Reich's seminal tape work It's Gonna Rain (1965) came about largely by accident. In January 1965, Reich had happened upon, and made a tape recording of, a young Pentecostal preacher giving a sermon in San Francisco's Union Square. Later, while experimenting with tape loops he had made of the sermon, Reich discovered the process of allowing two identical loops to gradually slip out of phase with one another. This phasing technique soon became an important element of Reich's style, as is evident from the tape work Come Out (1966) and numerous instrumental works of the late 1960s and early 1970s.
At the beginning of It's Gonna Rain, the preacher, Brother Walter, tells the story of Noah and how he was mocked for his folly in preaching and building the ark. After a brief pause, the work continues with several repetitions of the title phrase. This snippet then fragments into single words or parts of words. As a word or syllable is repeated again and again, its meaning yields completely to its abstract musical sound. The sound moves back and forth across the stereophonic spectrum, the left and right channels sliding smoothly in and out of unison. Soon, the listener's ear begins to fashion musical gestures out of the jumbled sounds as speech melts into pure aural texture.
As the second half of the work begins, Noah has boarded the ark and the door has been sealed. Brother Walter is increasingly frantic in his preaching; Reich emphasizes particular phrases by looping them: "They couldn't open the door ... they couldn't open the door... it had been sealed... but sho' 'nuff!" Reich's manipulations of the tape reflect the preacher's growing excitement, the phasings and splicing becoming more and more disjunct. In a fitting and perhaps tongue-in-cheek conclusion, the intelligibility of the text is completely drowned in a deluge of cacophony, which slowly fades to silence.