"Where the orchestrations are for dance purposes, which is to say that they're predominantly instrumentals, with brief one-chorus vocal refrains in the middle (an usually a modulation to the vocal), the Porter performances are essentially vocal from beginning to end. Adjustments had to be made for the key for Anything Goes (Porter sings, surprisingly, in B flat, a full step below the published key of C, which is the key that the orchestrations are in). Vince notes that this idea of improving upon a classical recording after the fact is also part of the Victor Records heritage; a decade or so after the death of Enrico Caruso, Victor house musical director Nathaniel Shilkret added a modern, electrically recorded symphony orchestra to some of the great tenor's originally acoustically recorded masters. Nearly 70 years later, Giordano and his Nighthawks - now expanded to include a three-piece string section - listened with headphones to the composer's performance of 70 years ago to make sure everything synced up perfectly."
