In later decades, he focused on coaching singers and served for 31 years as the accompanist of the charitable New York City theatre group, the Blue Hill Troupe.
He was, perhaps, best known for accompanying Camilla Williams in her performance of "The Star-Spangled Banner" immediately before Martin Luther King Jr. delivered his August 1963 "I Have a Dream" speech.
He accompanied recitals for several well-known singers, including Eileen Farrell, Roberta Peters, Martina Arroyo, Elisabeth Söderström, and Todd Duncan, as well as the harmonica player Larry Adler, among many others.
He notably accompanied Camilla Williams in her performance of "The Star-Spangled Banner" that preceded Martin Luther King Jr.'s speech "I Have a Dream" at the Lincoln Memorial in 1963 at the March on Washington for Jobs and Freedom.
[2] For the last thirty-one years of his career, Malloy served as accompanist for the Blue Hill Troupe, an amateur theater group based in Manhattan that performs Gilbert and Sullivan shows and musicals for charity.