3.3 Building on identity  (Page 2/3)

Thelonius Monk’s Ba-Lue Bolivar Ba-Lues-Are is based on the following theme:

In this excerpt, Monk’s fanciful improvisation leaves just enough details intact to make the original melody still recognizable.

Preserving the contour —the shape of a melody, but not its exact details—is another way of creating dynamic repetition.

Franz Schubert’s String Quartet in G opens with the following declamation:

Later in the work, the opening statement is restored, but with its details radically changed:

The originally jagged rhythms are “smoothed out;” the texture includes plucked strings; the harmony is different. The theme is recognizable primarily from its contour.

The opening theme of the first movement of Bela Bartok’s Music for Strings, Percussion and Celeste is presented by the violas, alone.

In the Finale movement, Bartok restores this theme. However, the initially cramped tune is “opened up:” While its contour is maintained, the arcs of its motion are now wider. The addition of lush harmony further invigorates the theme’s recurrence.

Changing clothing can make our physical appearance look different. Similarly, varying the harmony can “dress up” a theme in different ways.

Here are three different harmonizations of the Promenade theme from Modest Mussorgsky’s Pictures at an Exhibition .

In these excerpts, the nearly “unclothed” theme of Claude Debussy’s La fille aux cheveux de lin, is followed by two different harmonizations.

In tonal music, playing a melody in the opposite mode creates a very significant change.

This melody from Wolfgang Amadeus Mozart’s Symphony no. 38, “Prague,” is first played in Major, then switches to minor before reclaiming Major.

Conversely, the primary theme from the first movement of Franz Schubert’s String Quartet in a-minor is first played in minor, then switches to Major, before returning abruptly back to minor.

Thus, we have seen how a melody may be preserved, but its repetition varied through changes in speed, instrumentation, accompaniment and harmony.

The most rigorous and self-sufficient way of building on melodic identity is a canon. Like a round, a canon is based on imitation. In a round, the voices are cyclical: Like a merry-go-round, the voices keep replaying the same tune and underlying harmonic progression over and over again. A canon, on the other hand, is through-composed: Rather than turning around in circles, the melody and underlying progression keep moving forward. Thus, our distinction: rounds maintain the identity of a theme, whereas canons elaborate on it.

The third movement of Franz Joseph Haydn’s String Quartet in d-minor, Opus 76 No. 2 includes a two-voice canon: The violins play the lead line in unison, which the viola and cello then imitate in full. The canon is divided into two halves, each of which is repeated.

Twentieth century composers emphasized the plasticity of canons. In most traditional canons, each voice moves in a distinct register, like drivers staying in their lanes. In the following canon by Anton Webern, the voices constantly flip over each other. Like a game of “Three Card Monte,” it is easy to lose track of who is where. The repeated notes that recur throughout this brief movement are actually caused by the two canonic lines “bumping” up against each other.