Robert Helps, Piano, Isidore Cohen, Violin, and Willie Ruff, Horn Entered from booking ledger and New York Times concert listing and review. "Operas and Concerts for the Week." New York Times (1923-Current file), New York, N.Y., 1964. Klein, Howard. "NEW TRIO HEARD AT RECITAL HALL." New York Times (1923-Current file), New York, N.Y., 1964. chamber music performance 1964-12-05T17:30:00