Here is a performance of the Latin chant of the Cherubikon (Qui Cherubim mystice imitamur) by a group called "Gregoriana Amsterdam." It is the Offertory chant from the Missa Graeca, which is a rare and fairly obscure liturgy that was only ever used at a small handful of specific places on specific feasts (like St Denis) in medieval France. It is pretty cool, though. The Missa Graeca is interesting in that it was a Roman Mass with a Greek Ordinary and a Latin Proper. Hence, we have a Latin version of the Cherubic hymn, because the Offertory is a chant that is part of the Proper, and thus in the Roman Rite it is a different chant for every feast.