About
This webpage lets you enter a pitch collection, then looks for possible superset ‘Pressing scales’ (a term coined by Dmitri Tymoczko in his article Scale Networks and Debussy. Pressing scales, named after jazz theorist Jeff Pressing, are amongst the most common scales used in the expansion of tonality at the end of the 19th and beginning of the 20th century, especially by composers such as Debussy, Ravel, Stravinsky, Rimsky-Korsakov, Satie, Bartók and Messiaen, not to mention throughout jazz and popular music. They continue to be extremely influential and utilised by many contemporary composers. (Read more about the Pressing scales here.)
The seven possible Pressing scale collections are: DIA (Diatonic), ACOU (Acoustic), HARM MAJ (Harmonic Major), HARM MIN (Harmonic Minor), WT (Whole Tone), OCT (Octatonic) and HEX (Hexatonic).
To use, you need to choose a minimum of 3 pitch-classes for the subset search to begin. Scroll down to see a list of possible scales, and then click on one of the green buttons to select that scale. Once you have chosen a full scale, the app will also calculate related scales through Harmonic Evolution (scales that are related by changing one pitch class, akin to close modulations in tonal music such as the subdominant, dominant and relative minor/major) and Harmonic Contrast (scales that are related by changing a larger number of pitch-classes, akin to distant/dramatic modulations in tonal music).