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About Vi

Symmetry and Transformations in the Musical Plane

by Vi Hart

in Proceedings of the 12th Annual BRIDGES Conference: Mathematics, Music, Art, Architecture, Culture (BRIDGES 2009), Banff, Canada, July 2009, to appear

Paper in PDF format (1.3MB)

Abstract: The musical plane is different than the Euclidean plane: it has two different and incomparable dimensions, pitch-space and time, rather than two identical dimensions. Symmetry and transformations in music have been studied both in musical and geometric terms, but not when taking this difference into account. In this paper we show exactly which transformations apply to musical space and how they can be arranged into repeating patterns (frieze patterns and variations of the wallpaper groups). Frieze patterns are created intuitively by composers, sometimes with timbral color patterns or in sequence, and many examples are shown. Thinking about symmetry in the musical plane is useful not just for analysis, but as inspiration for composers.

Musical Compositions

One of my current composition projects is a seven-movement piano trio with one movement inspired by each of the seven possible geometric frieze patterns. Here are piano sketches of the first three movements:

Frieze pattern 1: Dizzy Hop Media player: Click to play (1 min 28 sec)
Frieze pattern 2: Hop Media player: Click to play (1 min 26 sec)
Frieze pattern 3: Sidle Media player: Click to play (2 min 18 sec)