Haydn's Missa brevis Sancti Joannis de Deo dates from c.1775 and was written for the Order of the Brothers of Mercy based in Eisenstadt. The mass is known for its distinctive 'Benedictus', which features elaborate soprano writing and an extensive obbligato organ part from which the work's alternative title, 'Little Organ Mass', derives. This edition includes the elongated 'Gloria' composed by Haydn's younger brother Michael, with Haydn's 31-bar original included as an Appendix.