This probably means that the written archetypes used for the transmission of chant did not indicate which alleluia should be sung on these specific dates.
It may be convenient to begin with the few cases in which an alleluia is always or nearly always assigned to a specific occasion.
The most obvious mode of investigating these alleluia series is the comparison of complete lists.
This fourfold alleluia resembles the alleluia antiphons derived from normally texted antiphons; the psalm tone is comparable to the normal second psalm tone.
So some differentiations are necessary for the history of the alleluia, too.
This is particularly evident in the alleluia, which could act as an akroteleuteon, an autonomous musical phrase like a refrain.
In a very few cases it may be possible to use the assignment of an alleluia as evidence of its place of origin.
The basic pattern consists of three verses: the first followed by one alleluia, the second by two, and the third by three.
