So we made it through the Yomim Noraim without hitting the trifecta. First time in years. The trifecta consists of three semi-recent melodies that are invariably used by chazzanim (usually for kedusha); Machnisei Rachamim, Shiru Lamelech, and Ein Aroch.
Couldn't make it through the whole season, though. We got the third one at Musaf yesterday. (We'd gotten the other two on Rosh Hashana and Yom Kippur.)