8.3 Phrase Groups and Double Periods: Tutorial

Beyond Sentences and Periods, multiple phrases can form larger groups as well.

Phrase Group

The term Phrase Group can be applied to any group of phrases that somehow, on account of their motivic length, phrase length, and/or cadences just seem to belong together, but not necessarily exhibiting the antecedent-consequent relationship found in a Period. A Phrase Group can be hard to define, but it’s the kind of relationship wherein you know-it-when-you-hear-it.

Sing through and analyze the melody below in Eb major, from the 18-century hymn, “Rock of Ages, Cleft for Me”:

Note how the delineations between the four separate phrases can be perceived . The first and last are four measures in length, while the inner two phrases are only two measures long. However, each phrase ends on the tonic note, implying an authentic cadence. While each of the four phrases is harmonically closed (none demand a consequent phrase to harmonic ally complete them), the four phrases seem to form a cohesive Phrase Group.

Double Period

The four phrases above form a kind of Phrase Group, belonging together without any antecent-consequent relationship. However, sometimes four phrases can form a group wherein the first two phrases set up an antecedent to be completed by the second two phrases which together form a consequent. This type of four-phrase group is called a Double Period.

Whereas the antecedent phrase of a Period will end in a half or other weak cadence, in a Double Period, it is the responsibility of the second of the four phrases to establish the feeling of an antecedent through cadential means.  Similarly, it is the responsibility of the fourth phrase to satisfy the expectation of a consequent through a strong authentic cadence. The cadences of the first and third phrases in a Double Period are of little consequence.

Sing through and analyze the D minor melody below. What kind of cadence concludes each of the four phrases?

Notice how the first phrase ends in an authentic cadence, yet the second ends in a half cadence. This half cadence binds the first two phrases together into a single antecedent double-phrase. The thirds phrase ends in a half cadence, but the antecedent pair of phrases is fulfilled by the authentic cadence concluding the fourth phrase.

Parallel versus Contrasting Double Periods

Much as two-phrase periods can be defined as parallel or contrasting based on the similarity, or lack thereof, of the melodic content of at the beginning of each of the two phrases, so can Double Periods. A Double Period is defined as parallel or contrasting based on the relationship between the beginnings of the first and third phrases. In the example above, the third phrase begins very much like the first and has thus been labeled a’. As a result, one may call this four-phrase group a Parallel Double Period.

The nature of the melodic material in the second and fourth phrases has no bearing on whether a Double Period is defined as parallel or contrasting, only the relationship between the first and third phrases.

Parallel Double Period phrase groups may include the following phrase relationships:
a b a’ b’
a b a c
a a’ a a”
a b a’ a” etc, so long as the first and third phrases are similar.

Contrasting Double Period phrase groups may include the following phrase relationships:
a a’ b a
a a b c
a b b’ a
a b b’ b”
a b c b’
a b c d etc, so long as the first and third phrases are different.