In the vast theatrical production of Antonio Caldara, La Clemenza di Tito stands out, a stylistically limpid and essential work of the composer's maturity, constructed on the carefully considered political and sentimental plot of the poetic text by Pietro Metastasio. This was the first musical version of the famous play, which later would be put to music by numerous composers, among which Gluck (1752) and Mozart (1791). At the Vienna court, where Caldara was assistant kapel-meister for the emperor Charles VI and Metastasio was poet laureate, the opera was presented on November 4th, 1734 for the emperor's name-day. Tradition dictated that on that day the most important production of the year would be put on in the court theatre, a fully-staged musical drama with the best singers and artists, using a libretto written by the poet laureate (up until 1730 Zeno, from 1731 Metastasio) on an ancient historical or oriental subject, generally rich in ideological and political dogma. For two decades, from the time he was hired to work at the imperial chapel in 1716 until his death, Caldara had the job of composing the music for the opera to be performed for this most important yearly festive event at the Habsburg court. Caldara and Metastasio were put to work together in the felix Austria of Charles VI, whose fortunate human and political fame started to decline a short time later with the loss of Naples and Sicily at the end of the war for Polish succession in 1734. An opera such as La Clemenza di Tito thus was intended to put before all of Europe the theme of imperial magnanimity, in the pompous stately climate of the Vienna court. Instead, Metastasio's play and even more Caldara's music accentuate motives of reflection and of true suffering, in the psychological twists and turns accompanying the doubts and difficulties of the protagonists, especially regarding Tito, true icon of a Christus patiens but also triumphant victor over evil which he fears not to confront face to face, sacrificing his private heart's yearnings to the public good.