“ Shield's most successful dramatic compositions were Rosina, The Mysteries of the Castle, The Lock and Key and The Castle of Andalusia. As a composer of songs he was in no degree inferior to his great contemporary Charles Dibdin. ”

“ In the meantime he turned his serious attention to composition, and in 1778 produced his first English comic opera, The Flitch of Bacon, at the Little Theatre in the Haymarket, with so great success that he was immediately engaged as composer to Covent Garden Theatre, for which he continued to produce English operas and other dramatic pieces in quick succession until 1797, when he resigned his office, and devoted himself to compositions of a different class, producing a great number of very beautiful glees, some instrumental chamber music, and other miscellaneous compositions. ”