A triad can contain the same three pitch classes in several different orders. Chord inversions change the bass note; voice leading describes how individual notes move between chords. Together, they give musicians finer control over harmonic movement.
Root position and inversions
C major contains C, E and G. With C lowest, C–E–G is root position. E–G–C is first inversion because the third E is lowest. G–C–E is second inversion because the fifth G is lowest. The chord remains C major in every case.
Slash chords
A slash chord specifies a chord and its bass note. C/E means C major over E (first inversion); C/G means C major over G (second inversion). Am/C means A minor with C lowest. The root names the chord, but the lowest sounding note of the complete texture determines its inversion.
The bass changes the analysis
An upper E–G–C shape alone is C/E, but if a separate bass instrument plays a still-lower C, the full harmony is C in root position. Equally, a sustained C–E–G above a bass E forms C/E. Analyse all instruments, not just the keyboard part.
Common tones
C major (C–E–G) and A minor (A–C–E) share C and E. Instead of jumping from C–E–G to A–C–E in root position, keep C and E and raise G to A: C–E–G → C–E–A. With C lowest, the second chord is Am/C. Only one voice moves.
A four-chord example
Root-position C–Am–F–G can be voiced as C–E–G | C–E–A | C–F–A | B–D–G. Those upper note collections correspond to C | Am/C | F/C | G/B if their written lowest notes are actually the lowest pitches in the arrangement. A bass track playing C–A–F–G underneath changes the full sonorities back into root-position chords.
How voices move
Voice leading follows individual strands rather than only chord labels. A note may remain as a common tone, move by step, or leap to a new register. Small movements can make transitions feel connected, but abrupt leaps, open spacing and large register changes may be more suitable for a dramatic arrangement.
Inversions in a MIDI Piano Roll
Programme a root-position progression, duplicate it and rearrange pitches by octaves without changing their chord-tone identities. The second version may retain common MIDI note rows between chords. Listen with and without a separate bass track to hear how that changes the musical interpretation.
Part of How Music Works — Volume 2.