Digestly

Jan 8, 2025

The space of all musical intervals

3Blue1Brown - The space of all musical intervals

The discussion begins by considering musical intervals as pairs of distinct notes, represented as points on a circle. This leads to the question of what mathematical object describes every unordered pair of points on a loop. Initially, points on a loop are labeled with values from 0 to 1, forming a unit square in the XY plane. By gluing the edges of this square, a torus is formed. However, to represent unordered pairs, further manipulation is needed. By folding along the diagonal and introducing a half twist, the structure transforms into a Möbius strip. This construction naturally encodes unordered pairs of points and is used in mathematical proofs, linking to a classic unsolved problem.

Key Points:

  • Musical intervals can be represented as unordered pairs of points on a circle.
  • Labeling points from 0 to 1 forms a unit square, which transforms into a torus when edges are glued.
  • To represent unordered pairs, the square is folded along the diagonal and twisted, forming a Möbius strip.
  • Möbius strips naturally encode unordered pairs of points, useful in mathematical proofs.
  • This concept is linked to a classic unsolved mathematical problem.

Details:

1. 🔮 Exploring Musical Intervals and Mathematical Spaces

  • Musical intervals can be thought of as pairs of points on a circular loop, suggesting a novel perspective on understanding these intervals.
  • The mathematical space describing unordered pairs of points on a loop — a concept rooted in musical topology — provides insights into musical intervals.
  • This approach suggests that examining musical relationships through the lens of mathematical topology can lead to more abstract and potentially richer understandings of music theory.
  • For example, consider how shifting or rotating these points may represent changes in harmony or melody, offering a framework for analyzing music beyond traditional methods.

2. 🔄 Understanding Loop Labels and XY Coordinates

  • Label all points on a loop with values ranging from 0 to 1. The labels 0 and 1 refer to the same point, highlighting the loop's continuous nature.
  • Use numerical labels as XY coordinates, describing a point in the unit square within the XY plane, offering a way to visualize and analyze positions on the loop.
  • This labeling system can be applied in various fields, such as computer graphics, where understanding and manipulating points on a loop is crucial for rendering shapes and animations.
  • For example, consider a circular animation path where each frame's position is determined by these XY coordinates, allowing for smooth transitions and precise control.

3. 🍩 From Squares to the Taurus: Gluing Edges

  • Gluing the left edge of the square to the right edge creates a continuous surface as these edges refer to the same point.
  • Gluing the bottom edge to the top edge aligns the y-coordinates, completing the transformation into a toroidal shape.
  • This process converts a square into the surface of a torus (donut shape) by ensuring all opposing edges are connected.

4. 🔀 Unordered Pairs and the Mobius Strip Transformation

4.1. Unordered Pairs in Geometry

4.2. Mobius Strip Transformation

5. 🧩 Mobius Strip in Mathematical Proofs and Unsolved Problems

5.1. Mobius Strip in Mathematical Proofs

5.2. Mobius Strip and Unsolved Problems

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