Rossini"s third opera seria for Naples, Armida, first performed November 9, 1817 and among his most unusual and beautiful stage works, is based on Tasso"s epic poem Gerusalemme liberata. From the performer playing Armida, Rossini demands singing of both spectacular virtuosity and great dramatic power. Some of his most sensual music occurs in Armida"s duets, two of which feature prominent introductions for solo violin and solo violoncello. Included in the large cast are six tenor roles (although they can be taken by four tenors, as they were at Naples). A highlight of Act III is the stirring trio for three tenors. Armida also requires two basses and gives conspicuous parts to men"s and women"s choruses. Unique among Rossini"s Italian operas is a large ballet, which occupies much of Act II, and the magical scenic effects called for in the staging. The critical edition presents Armida in its original form, reintegrating passages missing from the autograph score and restoring cuts made in printed editions.