Handel’s “Messiah” was written in late summer and premiered in April 1742, in Dublin; when it came to London, it was the following March. It may surprise those who associate it with bundling up for the cold that the oratorio was originally Easter music.

“Messiah” does end with the death and resurrection of Jesus, but its first part reaches a smiling climax with his birth. And for whatever other reasons, perhaps among them springtime competition from the likes of Bach’s “St. Matthew Passion,” the work crept — comprehensively, irretrievably — into December. It now dominates that month’s classical music calendar; nothing else in the repertory has such a firm grip on any season.

Its rollout in New York has become one of the city’s most predictable rituals. St. Thomas Church Fifth Avenue, with its pristine choir of men and boy trebles, tends to go first; its performances were last week. Then comes the New York Philharmonic, whose “Messiah run opened on Tuesday evening at David Geffen Hall and continues through Saturday.

Then the floodgates open: Over the next week come Handelian offerings by Kent Tritle’s Oratorio Society of New York (Thursday) and his Musica Sacra (Monday), the New Jersey Symphony Orchestra (Friday and Sunday) and the mighty amateur Masterwork Chorus (Sunday). Julian Wachner leads three performances of what may well be the most intense “Messiah,” with the forces of Trinity Wall Street Friday through Sunday. (They’re sold out, but Saturday’s performance will be streamed at trinitywallstreet.org.)