The Missa in Angustiis (Nelson Mass), composed in the summer of 1798, is one of six masses Joseph Haydn wrote between 1796 and 1802 in honor of Princess Marie Hermenegild, the wife of Prince Nokolaus Esterhazy II. The Latin title (Mass in time of peril) refers to the dismal situation during the Napoleonic Wars; the nickname of the work pays homeage to the victor of the Battle of Aboukir Bay, the English Admiral Nelson. Presented here for four-part choir with piano(or organ) accompaniment, the vocal lines in this edition follow those of the autograph score (housed in Vienna). The original notation has the solo and tutti passages in the same staves, distinguished by the markings "Solo" and "Tutti". In accord with modern performance practice, this edition prints solo and tutti lines in separate staves. The only amendment made to the original was to add a number of melidma slurs. The mass was originally orchestrated for strings, trumpets, timpani and obligato organ. The piano reduction in this edition thus makes only passing reference to the woodwind parts later added by Johann Nepomuk Fuchs. The notes in small print complement the full orchestral sound, however, and offer the pianist an option in performance.