We propose a phonologically well motivated theory of metrics that avoi
ds several problems (e.g, ternarity and center-headedness) with the tr
aditional analysis of Arabic metrics (al-Xalil dagger c. 791h; Maling
1973; Prince 1989). We propose that the content of a metrical position
is universally restricted to three prosodically motivated units. L, H
, LL, and that binarity holds at the levels of the verse foot and metr
on. This constrains the number of possible verse feet to nine and lead
s to the insight that the traditional Arabic verse feet are in reality
metra (pairs of verse feet). The different degrees of popularity of t
he Arabic meters (cf. corpora in Vadet 1955; Stoetzer 1986; Bauer 1992
), we argue, can be understood as a direct function of rhythmic well-f
ormedness. The best meters are all iambic (Ewald 1825, Jacob 1967 [189
7]; Fleisch 1956), the rhythmic advantage being that they, contain no
rhythmic lapse (Kager 1993), an important constraint in Arabic phonolo
gy and morphology generally (Fleisch 1956; McCarthy and Prince 1990b).
Relative rhythmic well-formedness is formally expressible under a sim
ple constraint-based analysis (cf. Prince and Smolensky, 1993).