Vanguard Records is a record label set up in 1950 by brothers Maynard and Seymour Solomon in New York. It started as a classical label, but is perhaps best known for its catalogue of recordings by a number of pivotal folk and blues artists from the 1960s; the Bach Guild was a subsidiary label.
In 1953, under the direction of John Hammond, the company began the "Jazz Showcase" series that concentrated on the mainstream jazz idiom, producing about two dozen recordings before it was wound down about 1958. Recordings made at the Spirituals to Swing concerts in 1938 and 1939 were finally released by Vanguard in 1959. The company only intermittently pursued recording jazz thereafter.Source: Wikipedia