Mr. Zaslav has been violist of the Kohon, Composers, Fine Arts, Vermeer, and Stanford String Quartets from 1957 through 1993.
With these groups he has been a faculty member at Brooklyn College, New York University, University of Wisconsin-Milwaukee (Distinguished Professor), Northern Illinois University (Professor) and at Stanford University.
Based in New York, the Kohon Quartet received the Grand Prix du Disque of the Charles Gros Societe, Paris in 1964 for their recording of the Alban Berg String Quartet #3. Also in New York, the Composers Quartet, with Mr. Zaslav as a founding member, were new music advocates. They performed and recorded works by Carter, Babbitt, Schuller, Shapey, Johnston, Crawford-Seeger, Sessions, Mamlok, Weinberg and others. Mr. Zaslav joined the Fine Arts Quartet in 1968. In addition to touring extensively and recording classic and contemporary repertory, they were responsible for commissioning and recording new works by Wuorinen, Babbitt, Johnston, Shifrin, Imbrie, Adler, Downey and Karel Husa, whose 3rd String Quartet received the Pulitzer Prize for Chamber Music in 1969.
In 1980 Mr. Zaslav joined the acclaimed Vermeer Quartet in Chicago. With them he toured widely as well and recorded Schubert, Beethoven, Dvorak, Brahms and Verdi. He joined the newly formed Stanford String Quartet in 1985 and toured and also recorded with them until 1993, when he decided to devote his time to performance and recording with the Zaslav Duo.
As quartet violist, he has recorded over 88 works of the classic and contemporary literature. Many of these are available on the Teldec, Orfeo, Columbia, Nonesuch, Everest, Laurel, Vox, CRI and Music & Arts Programs of America labels.