Frederick Oster has been active in dealing and appraising fine antique musical instruments for 30 years. In 1974 he founded Vintage Instruments, Inc. in Philadelphia for the appraisal, sale and restoration of rare and antique instruments, American and European fretted and stringed instruments, and antique woodwinds and brass. His violin shop, Frederick W. Oster Fine Violins, located in Philadelphia, specializes in the sale, appraisal, and restoration of antique violins and bows.
As a consultant to Christie, Manson and Woods in New York, he continues to advise clients and evaluate instruments for inclusion in Christie's London and New York musical instrument sales. He is also the national claims adjuster for the musical instruments program for the St. Paul Insurance Corporation, and consults nationwide for insurance companies, auction houses, symphony orchestras, collectors and museums, including the Metropolitan Museum of Art. Mr. Oster has also written various articles about musical instruments.