François Couperin, known as "The Great" to distinguish him from the other famous Couperins, was organist at St Gervais, Paris. (Someone from this family served that church in that capacity for 150 years.) He later served at the Royal Chapel at Versailles. Although most of his music is for harpsichord and other instruments, his first published music was for organ in the form of two masses. The short movements in the Mass for the Convents, with added notes and dotted rhythms in the style of the time, were meant to be played in alternation with the singing of chant by a choir. A typical Kyrie (Lord, Have Mercy) was nine-fold, beginning with the organ. This evening it will be performed in that fashion using the Kyrie from Mass VIII (de Angelis) at a pitch level found on French organs of the time, a whole step lower than modern pitch.