 In 1955, Paul Robyn left the group and Alvin Dinkin assumed the viola chair.In addition to their work in the Hollywood studio orchestras and recording classical repertoire, the HSQ members regularly performed as session musicians at the major record companies, including Capitol Records.At Capitol, they accompanied some of the leading pop performers of the era, most notably Frank Sinatra, for whom Felix Slatkin acted as concertmaster and occasional conductor on his now iconic Capitol recordings during the 1950s.