Of all the songs to get stuck in your head while hungover in the bath on a grey Friday morning.

Gow-day-tay, Gow-day-tay, Christu Sess-nah-toos, ex Maria virgin ay, Gow-day-tay.

Yes, it's that folk-meets-prog-meets-Gregorian-chant-Christmas-compilation-staple Gaudete. Steeleye bloody Span? Please, make it go away.