Messiah within the oratorio genre

Messiah was created within the specific genre of Handel's London theatre oratorios, and against a background of experience built up by both composer and audience prior to 1741. The theatre audience's expectation of a three-section evening's entertainment, lasting about three hours in performance with two intervals, was carried over from the three acts of Italian opera to the three parts of English oratorio. The perceived characteristics of Handel's oratorios were neatly summed up by Newburgh Hamilton in his Preface to the printed libretto for Messiah's ‘twin’ oratorio, Samson:

Even so, we may still be slightly surprised by Jennens's description of Messiah as ‘a fine Entertainment’.

Three features set Messiah apart from the main body of Handel's oratorios. The text, adapted from scripture (the Authorised Version of the Bible and the ‘Coverdale’ translation of the psalms associated with the Book of Common Prayer), includes no metrical or rhymed verse, such as was normally characteristic of aria texts for opera and oratorio. While the prose ‘verses’ of the scriptural sources have no metrical structure, they do nevertheless have a controlled rhetorical flow: English translations of the scriptures were, after all, intended as ‘performance texts’, to be read aloud at public worship.