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BACH / PITCH IN MOTION

Bach Inventions

Two voices. A conversation in neon.

C majorhome key · BWV 772

InventionTuning

0:00 / 0:00

Speed

Listen

Upper voiceLower voice

DEGREE ↑C6IVIIVIVIVIIIIIC5IVIIVIVIVIIIIIC4IVIIVIVIVIIIIIC3IVII

Press play to follow the notes.Watch the numbers rise and fall with pitch.

Numbers identify pitches: 1 = C … 12 = B. Roman numerals show scale degrees in each octave; the pitch beside each I marks the tonic.

Note frequencies

Upper voice

Press play to see this voice.

Lower voice

Press play to see this voice.

Odd numbers · blueEven numbers · pinkFixed pitch numbers: 1 = C … 12 = B, in every key and octave.

Read the numbers

Each number follows a played note, using fixed pitch numbers from 1 = C through 12 = B. Sounding notes glow brighter; earlier notes fade into the scrolling trail.

Solid trails follow the upper score voice; dashed trails follow the lower voice, even when they cross. Color follows the note’s number: odd is blue, even is pink.

The vertical axis uses pitch, with octaves kept separate. Roman numerals show scale degrees; chromatic notes carry ♯ or ♭ degree labels.

Degrees stay relative to C major throughout the piece. They show pitch relationships to the home key, rather than an analysis of each modulation.

Note frequencies and playback use the same tuning. The reference is A4 = 440 Hz in equal temperament; just intonation follows the invention’s tonic. Playback speed changes timing while preserving pitch.

Choose an invention, then press play.

Bach’s 15 two-part Inventions, BWV 772–786. MIDI editions by jeff covey and Allen Garvin via Mutopia. Grand Piano samples: tonejs-instruments. Sources & licenses · Open WTC

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