In 1965, Carlos graduated from Columbia University with a master's degree in music composition, and assisted Leonard Bernstein in presenting an evening of electronic music at the Philharmonic Hall. Carlos studied with Vladimir Ussachevsky and Otto Luening, two pioneers of electronic music in the 1960s; they were based in the Columbia-Princeton Electronic Music Center in New York City, the first of its kind in the United States. After Ussachevsky suggested to Carlos that she work in a recording studio to support herself, Carlos began working as a recording and mastering engineer at Gotham Recording Studios in New York City; she worked in this position until 1968. She called it "a really lovely occupation" and found it a useful learning experience.