St Philip's Singers and CAMRA Inc. have presented Handel's glorious Messiah a few times.
The ABC's Limelight has a list, with videos, of 'epic fails' in classical music. Mostly slapstick, and not funny. This one made me chuckle, as the humour is in the sound. With the excellent Colin Forbes at the helm, this did NOT not happen to our Messiah (!?).
The descent into chaos of this rendition of "Hallelujah!" is something to do with a transpose button, apparently.