found: Grove music online, viewed May 28, 2014 :(Offertory [offertorium, offerenda]; A chant of the Western Mass rites sung while bread and wine are prepared for eucharistic consecration. It is also the post-medieval name for the complex of priestly prayers and ritual actions (mixing of wine and water, incensation, washing of the hands) that took place during this part of the Mass. In its full medieval form the offertory chant consisted of a choral refrain in richly neumatic style with two or three neumatic--melismatic verses sung by a soloist. The latter part of the refrain (known as the repetendum) was repeated after each verse. Related to the offertory of the Roman Mass are the Ambrosian offerenda, the Mozarabic sacrificium and the Gallican sonus)
