Second Notation: Metric Changes (Stravinsky's Method)

Definition: Gathering ametric rhythms into normal measures but frequently changing time signatures to accommodate rhythmic irregularity, piling up metric changes to represent rhythmic complexity.

Messiaen's Treatment: In orchestral contexts, when all performers play the same rhythms and these rhythms gather into normal measures, one can pile up metric changes—the approach Stravinsky employed in Le Sacre du Printemps. These changes of meter are very tiring for the orchestra conductor.

Messiaen used this second notation in his Offrandes oubliées.

Modern Context: This represents Stravinsky's solution to notating irregular rhythms within metric frameworks—constantly changing the meter to match rhythmic accent patterns. The technique creates:

• Additive rhythm notation: Each measure's duration determined by the specific rhythmic pattern it contains rather than by recurring metric scheme
• Metric irregularity: Prevents establishment of predictable metric hierarchy while maintaining measure-by-measure organization
• Conductor challenges: Rapid metric changes require constant attention to changing beat patterns and subdivisions

Contemporary composers continue using this approach (Bartók's "Bulgarian rhythms," Carter's metric modulations, Birtwistle's irregular meters), though it shares the same fundamental compromise as Messiaen's fourth notation—using metric notation for ametric music.

The technique works best when:

• All performers share the same rhythm (homophonic textures, orchestral tutti)
• Rhythmic patterns are relatively brief (allowing frequent metric adjustment)
• A conductor coordinates the ensemble

It becomes unwieldy with extended passages in irregular meters or complex polyrhythmic textures where different parts would require different meters.

Examples: No specific examples provided; Messiaen references Offrandes oubliées.