MusicReasonChords and Harmony
Which tone is in the bass at this inversion?
Choose a chord and an inversion number. This tool rotates the chord's own tone set so that tone sits lowest, then stacks the remaining tones above it in ascending octaves, exactly the ordering a pianist reading a slash chord would expect.
Answer
Understand
Inverting a chord never changes which pitch classes it contains, only which one sounds lowest. A triad has three possible bass tones (root position, first, and second inversion); a seventh chord adds a third inversion, with the seventh itself in the bass. The ordering above the bass always ascends by octave from wherever the bass note landed, so no tone above the bass ever sounds lower than the bass itself.
Worked examples
A C major7 chord (C, E, G, B) in root position sounds C at the bottom. First inversion rotates to E, G, B, C, with E lowest and the octave-displaced C now on top. Second inversion rotates to G, B, C, E, and third inversion, unique to seventh chords, rotates to B, C, E, G, putting the chord's seventh in the bass.
Method and limitations
The chord's tones come from the same locked chord-formula vocabulary Chord Builder uses. Inverting rotates that ordered tone list so the requested position is first, then assigns each successive tone the lowest octave register that still sounds above the one before it, guaranteeing a strictly ascending stack with no accidental doubling or crossing. This tool does not choose voicing spacing beyond simple ascending octaves; wider spreads, doubled tones, or specific left/right-hand splits belong to the dedicated voicing explorers.
Inversion is written differently depending on context: a lead sheet marks it with a slash chord (C/E), while a Roman-numeral analysis marks it with a figured-bass-style superscript (I6). Both describe exactly the same rotated tone set this tool computes; the choice of notation is a presentation preference, not a difference in the underlying chord. A chord that has been reduced to only two of its own tones, such as an omitted-fifth voicing, has fewer possible inversions than its full formula would suggest, since an inversion needs an actual tone present to serve as the bass.