John Casper Heck

John Casper Heck was a music theorist active in London during the second half of the eighteenth century. His birth is placed in Germany around 1740 and his death in London in 1791, although both dates are approximate and not precisely documented. What little is known of his life comes from the archives of the Royal Society of Musicians, which record his marriage to Hannah Brown in 1760 and his admission to the society in 1772.

In 1779 Heck applied to the institution for assistance, claiming a paralysis which, by his own account, prevented him from playing, walking or speaking clearly. His writings reflect a direct knowledge of German music and theory. His Musical Library includes a catalogue of works by Johann Sebastian Bach and a fragment of the fugue from The Art of Fugue, as well as one of the earliest descriptions in English of a hierarchy of rhythmic structures with segments of intermediate length between the subject and the complete movement.

According to some accounts, he is credited with English translations of parts of treatises by Mattheson, Quantz and Fux, published in London in the second half of the eighteenth century. His didactic works include texts on basso continuo, fingering and harmony, as well as a musical dictionary of 1784 that was probably left unfinished.