What is bimodality?

bimodality is the practice of using notes from two different tone classes in a single musical composition, which makes the key or tonal center more ambiguous. It is therefore a technique designed to provide more interesting harmonization and move the boundaries of tonal music. It is considered to be a more modern method and is closely related to the musical concept of polytonality.

Bimodality can use any two classes of the playground of the composer's choice. Classes may not be what modern composers and listeners know as "main" or "smaller" standards. They can also use modes developed by ancient rivers, including Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian and Ionian. Other possible classes include the whole tone and pentatonic standards. For example, the notes of the Lydian regime starting at FJsou F, A, B, C, D and E. Notes of the Dorian regime starting on D are D, E, F, G, A, B and C. If one player played in Lydian for measures one to four and the other player performed in LocrianA day up to four, a piece was truly bimodal. If the work was played by everyone in Lydian to measure one to four and all play in Locrian in measures of five to eight, but this piece would not correspond to the bimodal definition.

normally, at work with only one regime or tonal center, all lines cooperate in the same harmonic procedure, although each line can be rhythmically and melodically independent. This is no longer true in bimodality. The harmonies present may be useful either by the playground class. This often leads to a high level of dissonance, or at least, creates more complex chords.

For a composer who does not want so much clash between playgrounds, a challenge of bimodality is to find common features and relationships between the class classes and do not deviate from them. For example, using Lydian on F and Dorian on the example D, the composer might notice that D a smaller chord with notes D, F and and is possible in both modes. In Lydian would be dA smaller chord based on the fifth comment of the mode. In Dorian it would be built on the first comment of the mode. The composer might also notice that the distance between the first two notes of both modes is a third that forms a media relationship.

bimodality should not be confused with the mixing of the regime. In mixing the regime, composers simply borrow harmonies between the main key and its relative minor. This gives the composer a greater ability to add more colors to work and use different types of progression and chord relationships, but the regimes alternate instead of being present at the same time. The fact that the composer cannot use melodies or harmonies from both the main and smaller keys at the same time distinguish this technique from bimodality.