My understanding is that it is illicit for a priest to sing the words of the consecration. Is it so, and where is it written?
Until Vatican II, the Latin rite was the only rite that did not sing the consecration. Now, however, the whole Eucharistic Prayer can be sung—according to music approved by the local bishop. This URL provides documentation: http://www.zenit.org/english/visualizza.phtml?sid=88797