The alleluia was the last proper chant of the Mass to be standardized. Through the twelfth century and beyond, different churches assigned different alleluias to the same Masses, and the composition of new alleluia chants flourished throughout the latter Middle Ages. The Masses from Easter to the octave of Pentecost witness this. A collation of ca. 200 manuscripts demonstrates that identical series of chants are to be found only in sources emanating from the same church (or churches in the same city). Most of the alleluia chants from the eleventh century onward have New Testament or non-scriptural texts, as opposed to the psalmic texts of the earlier post-Pentecostal alleluias. The musical style is varied, ranging from the richly melismatic manner traditionally associated with the alleluia to much more modest melodies with few or no large melismas. A number of the latter can be associated with the reforms of Guillaume de Volpiano at Dijon and in Normandy in the years after 1000.