The problem of metrical forms and the prosody of the earliest Latin
hymns, in general, is a phase of the same problem affecting Latin poetry
as a whole. The subject is both complicated and obscure, entangled with
that of Latin rhetorical prose style, the transition from the
quantitative accent of ancient classical poetry to the stress accent of
medieval and modern verse and with the origin of rhyme. It is a problem
for specialists among whom opinions are now divergent. Toward a
practical understanding of the metrical values of the hymns of Hilary,
Prudentius, Ambrose and Fortunatus, the pragmatic test of what is
singable may be applied. The ancient balanced rhythms of Semitic poetry
as illustrated in the Hebrew psalms had been sung for generations. The
metrical lyrics of ancient Greece were sung to an instrumental
accompaniment as were the Latin lyrics of the Golden Age of Rome. These
highly polished classical forms were for the elite. Of popular poetry
which was sung in the period immediately preceding the appearance of the
Latin hymn, very little is known. The early writers were experimenters.
Hilary used classical meters with alterations, of which the trochaic
tetrameter catalectic proved most acceptable.[10] It is illustrated in
_Adae carnis gloriosae_ and also in hymns by Prudentius and Fortunatus.
Prudentius used a variety of meters in addition to the trochaic which
proved adaptable in actual liturgical practice but by that time stress
accent was beginning to obscure the original quantitative values.
Ambrose used the unrhymed iambic dimeter, a simple and singable form
which has been in vogue ever since, at first unrhymed after the original
models and later rhymed. The popular trochaic meter familiarized by
Hilary, Prudentius and Fortunatus, when transformed by stress accent and
rhyme, is easily recognized both in Latin and the vernaculars.
Fortunatus popularized the elegiac meter in hymns for a thousand years
by demonstrating its use in _Tempora florigero_. Prior to the ninth
century revival of hymnody, the Ambrosian hymn, considered as a metrical
model, in comparison with all other existing models, dominates the field
equally with its prestige as an expression of Christian theology and
devotion.