Los Angeles quartet Ambrosia, whose founding members included guitarist/vocalist David Pack, bassist/vocalist Joe Puerta, keyboardist Christopher North, and drummer Burleigh Drummond, fused symphonic art rock with a slickly produced pop sound. After forming in 1970, the group was discovered in 1971 by Los Angeles Philharmonic conductor Zubin Mehta, who featured Ambrosia as part of a so-called All-American Dream Concert. However, it took them four more years to get a record contract; Ambrosia was released in 1975 and spawned the chart singles "Holdin' on to Yesterday" and "Nice...