Was vowel quantity observed when singing?

Question

It's well established that vowel length was phonemic in Latin, and that it played an important role in poetic verse. It seems probable to me that it also mattered when singing, but do we have evidence that it was? Or evidence to the contrary?

Some current languages drop some otherwise phonetic aspects of their pronunciation when singing. For instance, while Cantonese or Vietnamese, which are tonal languages, do take care to match tones with melodic contours in songs, Mandarin Chinese does not, and tones are largely ignored when singing. Japanese has phonemic vowel length, and largely keeps its while singing, but things occasionally get squeezed or stretched to fit with the music's rhythm, and geminated consonants occasionally get replaced with a lengthening of the preceding vowel (as you cannot carry a lengthy melodic note on a consonant).

So I could imagine Latin song lyrics strictly keeping vowel length and rhythmic length in sync, or maybe doing syllable length the way poetry does, or starting there but occasionally bending the rules a little, or doing away with that altogether and letting the musical rhythm dominate. But do we actually know how such things were handled in classical times?

Answer 1

Welcome to the sight! Since, no one has ventured an answer, I will attempt a partial one.

I know of no songs preserved from the age of classic Latin, but have not looked into the matter to know whether any exist. I do know that we have some Greek songs set to music from at least the Hellenistic Greek period, like the Seikilos Epitaph. In this song, the match between the Ancient Greek pitch accent and melody and between vowel length and note length is excellent. The match between note length and syllable weight is perfect.

As best we understand it, Latin had more of a stress accent than a pitch accent. The music could have replicated stress more with modulation in rhythm than with the type of changes in melody that were necessary for the Seikilos Epitaph and the phonology of Koine Greek. As in English, the match between stress and rhythm need not be perfect, and it is more of a matter of not forcing words into an unnatural stress rhythm than having actually to reproduce the spoken stress rhythm and intonation. I would assume the same possibilities apply to how much vowel length needed to be respected in Latin. My feeling for Mandarin is that although tone melodies can largely be ignored, stress rhythms still must be respected.

In a quick search, the earliest Latin music I could find were the hymns attributed to Amrose of Milan from the 4th Century CE. Apparently, these were written in Iambic dimeter and so had to take into account vowel and syllable length in their composition even at this quite late date in Latin. This composition, however, could have been a matter of using preserved knowledge of poetic meters, rather than respecting existing spoken rhythms. Especially if they were inspired by older Greek models.

Here is a one of the songs, Aeterne rerum conditor. To my ear, there is not a close respect for vowel or syllable length as was done for the Seikolos Epitaph. However, there is some concordance beyond what is necessary for the stress and maybe driven by the poetic meter. Again, at this late date, I am not sure how much vowel length was actually respected in speech. If I recall correctly, some mergers had already happened in North African Latin, where ōs and ŏs had merged in pronunciation in the 4th century.