The third antiphon, In caelestibus regnis, is a unique surviving work for alto and strings. It is an example of the short type of piece that Pergolesi might have found time to write in between his operatic commissions when he was maestro di cappella to the Duke of Maddaloni. (The Duke, himself an amateur cellist and the dedicatee of Pergolesi’s Cello Sonata, might well have enjoyed playing the work’s leaping bass line.) A setting of the text of an antiphon for a common saint at First Vespers (with the Alleluia suggesting Eastertide as the most likely period in the Church calendar), In caelestibus regnis shows a different side to Pergolesi’s sacred music, and another contrasting compositional facet of this extraordinary composer.
from notes by Robert King © 1988