For projects of lighter music, however, Gerhardt assembled freelance musicians along with players from various London orchestras — always a plenitude in the U.K. capital, where stringent U.S. union restrictions did not apply and salaries were cheaper, with fewer permanent jobs available nationwide. Early on he called these recording orchestras the London Promenade (basically London Philharmonic personnel) or the RCASO. In addition to concert, concerto, and bon-bon repertoire, Gerhardt arranged and conducted ten stereo LPs of film music for the Digest that were released in two volumes. Their quality so impressed Marek's successor, R. Peter Munves, that he commissioned Gerhardt to make an LP of The Classic Film Scores of Erich Wolfgang Korngold for RCA's own Red Seal label. Throughout what became a series of 15 Classic Film Scores, Gerhardt's producer was the late George Korngold, son of the composer, to whom concertmaster Sydney Sax had introduced him.
Subsequently Chesky Records leased some of the earlier Readers Digest material for a superbly remastered and custom-pressed series of discs, on one of which the name National Philharmonic first appeared, dated 1967. The actual year of origin, however, seems to have been 1972, starting with the RCA Korngold collection. That trailblazing film series was completed by 1985, although Gerhardt himself recorded a Wagner collection with the NPO for Chesky as late as 1995.
After his farewell Wagner CD, Gerhardt retired to California, where he died four years later. From the available evidence, his informal NPO also gave up the ghost after 25 years, when the classical market went soft worldwide in the later '90s, and London players with permanent posts clung to them like becalmed sailors, waiting for a breeze to rescue them from irrelevance as a professional breed.