Prelude in C Major: Gesture Chord Study

Play Chord States, Not the Prelude's Arpeggio

This Prelude in C Major lesson is an original harmony-control study in Bach's keyboard context. The browser plays simultaneous chord voicings, not the repeating broken-chord pattern of the score. No recording, melody, score excerpt or piano accompaniment is included. Use the route to understand what changes when the root stays fixed but the voicing moves.

Begin with C: degree I, major world, one finger. For C/E keep the same degree and wrist, then raise two fingers. The engine changes the lowest note from C to E while keeping the C-major chord identity. A slash chord asks for an inversion; it does not ask you to move the left hand to the bass note's degree.

The first two cards are your controlled experiment. If the left degree changes, repeat them with the left palm anchored. If only the bass changes but the chord colour remains major, the comparison is working. Neither target requires the thumb, so keep the normal register throughout this opening test.

• Target 1: C — degree 1, major world, 1 right-hand finger, normal octave.
• Target 2: C/E — degree 1, major world, 2 right-hand fingers, normal octave.
• Target 3: Dm7 — degree 2, minor world, 3 right-hand fingers, normal octave.
• Target 4: G7 — degree 5, major world, 4 right-hand fingers, normal octave.
• Target 5: Em — degree 3, minor world, 1 right-hand finger, normal octave.
• Target 6: Am — degree 6, minor world, 1 right-hand finger, normal octave.
• Target 7: G7 — degree 5, major world, 4 right-hand fingers, normal octave.
• Target 8: Cmaj7 — degree 1, major world, 3 right-hand fingers, normal octave.

Review the hand-control map →

Build Two Different Seventh Chords

Dm7 uses II, minor world and three fingers, producing D–F–A–C. G7 uses V, major world and four fingers, producing G–B–D–F. They share D and F as pitch classes, but require different root, world and quality inputs. Prepare those three changes separately before attempting one continuous motion.

At the section break, preview Em: III, minor world and one finger. Am follows on VI with the same minor world and one-finger quality. This is the second controlled comparison: unlike the C-to-C/E opening, now the right hand stays fixed and only the root degree changes.

The second G7 must match the first G7 despite arriving from Am rather than Dm7. Compare the feedback chips, not just the sound. The route's final Cmaj7 is I, major and three fingers; it includes B, unlike the starting C triad. Treat that different ending as an intentional listening comparison, not as a claim about Bach's exact ending.

Practise chord inversions → · Compare seventh qualities →

A Listening Worksheet You Can Repeat

First ask which hand should stay still. C to C/E keeps the left hand still; Em to Am keeps the right hand still. Complete each pair slowly and name the changed property. This makes accidental movement easier to notice than running all eight targets at speed and guessing why a card stalled.

Next ask whether the seventh is major or minor above its root. The three-finger major world gives Cmaj7 with B, while four-finger major world gives G7 with F. Three fingers in the minor world gives Dm7. The same word seventh therefore does not imply one universal finger shape.

Finally compare starting C and ending Cmaj7. The chord root and world are identical, but the right hand changes one to three. Listen for the added B colour and watch the quality label. Keep computer volume moderate; a louder output is not evidence of a more accurate hand state.

Fix recognition problems → · Set up the camera →

Complete an Accurate Harmony Pass

Use the optional 72 BPM click only once the individual comparisons are reliable. The guided system waits for a stable recognized state and does not measure whether you played an arpeggio on time. You may spend several beats preparing a card; the success condition is still the correct degree, world, quality and octave.

All targets use normal octave. Test the final Cmaj7 once with the thumb extended: the low state should stay pending. Fold the thumb to recover without changing the other properties. If confirmation still fails, check three fingers rather than two and verify major rather than minor wrist world.

Finish without Skip, then repeat and count corrections at the two controlled comparisons and the repeated G7. A reduction in corrections is a useful practice outcome. This page cannot replace a piano score lesson for Prelude in C Major; it teaches a smaller, explicit skill: hands-free recognition of roots, inversions and seventh colours.

Browse all exercises → · Adjust the practice click →