Slash Chord

In popular music a slash chord or slashed chord, also compound chord, is a chord whose bass note or inversion is indicated by the addition of a slash and the letter of the bass after the root note letter. It does not indicate "or".

For example, a C major chord (C) in second inversion is written C/G, which reads "C slash G", or "C over G". If B were the bass it would be written C/B (making a major seventh chord in third inversion), which is read "C slash B", or "C over B". Some chords may not otherwise be notated, such as A♭/A. Thus, a slash chord may also indicate the chord form or shape and an additional bass note.

In popular music, where the particular arrangement of notes is less important than some other forms, slash chords are generally used only when the specific bass note is important. A common example in guitar based music is in the I-V-VIm progression. By placing the third of the V chord in the bass, a descending scale, also known as a walkdown, is created in the bass. For example, in the key of G major this would be the chords G, D/F♯, Em. That progression has the descending bassline G, F♯, E. This type of slash chord contains diatonically occurring notes. In traditional notation it would be written using figured bass symbols.

Some sources notate slash chords with a horizontal line, although this is discouraged as this type of notation can also imply a polychord.