How did Milton Babbitt use the RCA synthesizer in his compositions?

Milton Babbitt utilized the RCA Electronic Music Synthesizer primarily to achieve precise control over all elements of his compositions, rather than simply to generate novel sounds.1

As a leading proponent of total serialism, Babbitt sought a medium that allowed him to realize his music with greater accuracy than traditional performance methods permitted. The RCA synthesizer facilitated this by using an information input mechanism where the composer punched sets of instructions—specifying properties such as pitch, tone color, vibrato, and envelope shape—onto a wide roll of paper tape. This process allowed Babbitt to define musical elements for every 1/30th of a second, enabling him to execute complex musical changes with a level of precision beyond human capability.123

Babbitt could interrupt the programming process at any time to listen to, edit, and correct the material before finalizing the "master score" on the paper tape. His notable works created using this machine include Composition for Synthesizer (1961), Vision and Prayer (1961), Ensembles for Synthesizer (1963), Philomel (1964), and Phonemena (1974).21