AMBROSIAN CHANT. — This is the chant currently used in the Ambrosian liturgy. In antiquity its diffusion was much wider, extending as far as Benevento and Montecassino, although the Ambrosian chant was always synonymous with the Milanese. In reality, one cannot affirm that the chant, like the liturgical arrangement itself, is the work of St. Ambrose; however, it is certain that in the psalmody, hymnody, and other parts, the latter provided a personal direction. Nevertheless, everything leads us to believe that by the 6th century at the latest, both chant and liturgy had their own distinct character, different from that established by Pope St. Gregory for Rome.
As for its origin, although many details remain imprecise, it is believed to have responded—without excluding Eastern influences and some Gallican elements—to a more or less Latin tradition. In this way, one can say that there was a Roman musical tradition, which was stylized differently in Rome and in Milan, perhaps also due to the differing importance of the two centers. Regarding rhythm, it is certain that the tradition was the same; indeed, the oldest Ambrosian musical manuscripts employ, so to speak, the same North Italian notation, which shows great affinity with the St. Gall notation used at Bobbio, as well as the same additional rhythmic signs.
In its modal aspect, the Ambrosian chant bears even more witness to the ancient theory than the Gregorian chant, before it was adjusted and systematized in the Middle Ages; it is more in keeping with the Latin genius, with its free rhythm and the ancient theories of Hellenic harmony. The two chants, Ambrosian and Gregorian, although they may be said to belong to the same liturgical music, each have their own distinct style and formulas. In the Ambrosian chant, the melismas are generally more prolonged, composed of more conjunct intervals, and more closely resemble the Byzantine form. The manuscripts on which a critical edition of this chant has been established are relatively numerous and date back to the 9th and 10th centuries. The notation, from the primitive form, developed until it assumed Gothic shapes; today it can be legitimately presented with a common Latin neumatic tradition.
Noteworthy in the modality of the Ambrosian chant is the absence of any numerical indication of the modes at the beginning of the melody; this better corresponds to its primitive character. The psalmody does not have its own melody for the *mediante*, and as the dominant for the singing of the psalm, it logically chooses the note that has most dominated in the antiphon, with which it must form a harmonious and liturgical whole.
As for its aesthetics, there is, more than in the Gregorian chant, a great diversity of formulas for the different liturgical moments. Its expression, although at times of extraordinary simplicity, is at other times more intense, more felt, more daring; therefore, the appellation of “harsh chant” applied to it in an era when the true Ambrosian chant was unknown is completely false. Overall, it is a more primitive, more spontaneous, less contrived musical expression than the Gregorian.