The Double-period

A third method consists in expanding the period

into a double-period (precisely as the phrase was lengthened into a

double-phrase, or period), by avoiding a perfect cadence at the end of

the second phrase, and adding another pair of phrases to balance the

first pair. It thus embraces four coherent phrases, with a total

length of sixteen measures (when regular and unextended).



An important feature of the ouble-period is that the second period

usually resembles the first one very closely, at least in its first

members. That is, the second phrase contrasts with the first; the

third corroborates the first; and the fourth either resembles the

second, or contrasts with all three preceding phrases. This is not

always--though nearly always--the case.



The double-period in music finds its poetic analogy in almost any

stanza of four fairly long lines, that being a design in which we

expect unity of meaning throughout, the progressive evolution of one

continuous thought, uniformity of metric structure (mostly in

alternate lines), the corroboration of rhyme, and, at the same time,

some degree and kind of contrast,--as in the following stanza of

Tennyson's:



Phrase 1. The splendor falls on castle walls,

Phrase 2. And snowy summits old in story;

Phrase 3. The long light shakes across the lakes,

Phrase 4. And the wild cataract leaps in glory.



The analogy is not complete; one is not likely to find, anywhere,

absolute parallelism between music and poetry; but it is near enough to

elucidate the musical purpose and character of the double-period. And

it accounts for the very general choice of this form for the hymn-tune.



The following illustrates the double-period, in its most regular and

convincing form (Beethoven, pianoforte sonata, op. 49, No. 1):--



Each phrase is four measures long, as usual; the first one ends (as in

Ex. 50) with one of those early, transient perfect cadences that do not

break the continuity of the sentence; the second phrase ends with a

semicadence,--therefore the sentence remains unbroken; phrase three is

exactly like the first, and is therefore an Antecedent, as before;

phrase four bears close resemblance to the second one, but differs at

the end, on account of the perfect cadence. The evidences of Unity and

Variety are easily detected. The main points are, that the second pair

of phrases balances the first pair, and that the two periods are

connected (not separate periods). See also Ex. 53, first 16 measures.