We must distinguish between isometric and anisometric stanza forms. In the former the whole stanza consists of four-beat alliterative lines, commonly rhyming according to a very simple scheme (either a a a a or a b a b). In the latter four-beat long lines as a rule are combined with isolated lines of one measure only and with several of two measures to form the stanza. The two-beat verses frequently have a somewhat lengthened structure (to be discussed further on sections on the epic stanzas), in consequence of which many of them having theses with secondary accents can be read either as even-beat verses of three measures or as three-beat verses on the model of those in King Horn. The four-beat alliterative lines, on the other hand, are mostly of more regular structure, the distances between the first and second arsis not being so unequal and the theses as a rule being disyllabic. The anacrusis too in these verses admits of a somewhat free treatment. The difference, however, between the first and second hemistich is less conspicuous than it was in those forms of the Middle English alliterative line before mentioned. Alliteration, on the other hand, is abundantly used.
The main rhythmic character of the verse is again indicated here by the frequent occurrence of the types A and A1. The types B C, B C1, C, C1, however, likewise occur pretty often, and the two last types present serious obstacles to the assumption that the lines of these poems were ever recited with an even beat. But how exactly these poems were recited or to what sort of musical accompaniment can hardly be definitely decided in the absence of external evidence.
The first verses of a West-Midland poem of the end of the thirteenth century (Wright’s Political Songs, p. 149) may serve as a specimen:
Ich herde mén vpo móld | máke muche món,
Hou hé beþ iténed | of here tílýnge:
Góde ȝeres and córn | bóþe beþ agón,
Ne képeþ here no sáwe | ne no sóng sýnge.
The second hemistichs in ll. 2 and 4 belong to type C. In other poems also, with lines of more regular rhythm (chiefly type A), this type may be met with now and then, e.g. in a poem published in Wright’s Specimens of Lyric Poetry, p. 25, especially in the second hemistich, e.g. haueþ þis mái mére, line 9, and þe gýlófre, line 40, þat þe bór béde, line 44.
It is not difficult to distinguish such rhymed four-beat alliterative lines from those of four measures which have fairly regular alliteration, for the long line of the native metre always has a somewhat looser fabric, not the even-beat rhythmic cadence peculiar to the iambic verse of four measures, and, secondly, it always has a caesura after the first hemistich, whereas the even-beat verse of four measures may either lack distinct caesura or the caesura may occur in other places in the verse as well as after the second arsis. This will be evident by comparing the following four-beat verses of the last stanza of a poem in Wright’s Spec. of Lyr. Poetry, p. 31:
Ríchard | róte of résoun rýght,