Ostinato : its structural characteristics, functions within the related textures and correlation with the musical forms of selected compositions by Igor Stravinsky

The purpose of this study was to analyze Igor Stravinsky's L'Histoire du Soldat (1918), Symphony of Psalms (1930), and Agon (1957) to determine and compare the structure of their ostinati. Additional aspects of this study were to determine the functions of ostinati within their related textures, to determine the musical forms of the compositions, and to determine the extent to which ostinati and musical forms were interrelated in these compositions.

Each ostinato in these compositions conformed to one of the following contour classifications:

I sawtooth V horizontal

II arch-shaped VI ascending

III multiple arch VII descending

IV wedge VIII hybrid

Rhythmic durations for all pitches within individual ostinati were usually constant. Minor alterations of the rhythmic consistency were not uncommon in L'Histoire du Soldat, but such alterations were not an important fea-ture of ostinati in either Symphony of Psalms or Agon. The majority of ostinati in L'Histoire du Soldat and Symphony of Psalms served an accompanimental role within a homophonic texture, while in Agon,/u> most ostinati functioned as an element in a polyphonic texture.

A majority of each composition's ostinati incorporated alteration as an element of their presentation. Primary types of ostinato pattern alteration include: minor adjustments of pitch and/or rhythm, adjustment of the time span between statements of an ostinato pattern, abbreviation, and extension.

The musical forms of most movements within these compositions are a group of parts or part forms. Most ostinati begin at or near a point of phrase initiation and conclude at the end of the same phrase.