Robert Loren Marsteller (October 31, 1918 – June 18, 1975) was a graduate (cum laude, 1940) of the Eastman School of Music, where he studied under Emory Remington. He was principal trombonist with Leopold Stokowski’s All-American Orchestra (1940-41), and the National Symphony Orchestra, Washington, D.C., under Hans Kindler (1940-42).
During World War II he joined the U.S. Naval Reserve in 1942 and performed in the USO’s Little Symphony in San Diego conducted by Frederick Fennell (1942-44). Later he was transferred to the Naval Station, Adak Island Band, Alaska (1944-45) and was honorably discharged in 1945.
He joined the Los Angeles Philharmonic Orchestra in 1946 and performed as principal trombonist until his retirement in 1971. He worked under Alfred Wallenstein, Eduard van Beinum, and Zubin Mehta. He taught at the University of Southern California from 1946 until his death, first as Lecturer, then Associate Professor, and finally Professor.