Root (chord)


![Assumed root, Am7/B: A minor ninth chord without root and with B in the bass.[9]
Play Am9/B, Am7, then full Am9.](/uploads/202502/08/Assumed_root_A_minor_ninth_chord3433.png)
![A comparison of the diminished 7th Play and dominant 7th[13] (♭9) Play chords.](/uploads/202502/08/Diminished7thandMinor9thComparison3433.png)
In music theory, the concept of root denotes the idea that a chord could be represented and named by one of its notes. It is linked to harmonic thinking, that is, to the idea that vertical aggregates of notes form a single unit, a chord. It is in this sense that one can speak of a "C chord", or a "chord on C", a chord built from C and of which C is the root. The root needs not be the bass note of the chord: the concept of root is linked to that of the inversion of chords, itself deriving from the notion of invertible counterpoint.