Bebop Dominant

Why the eighth note is there

A seven-note scale played in eighth notes shifts by one position every bar: start C D E F G A B♭ on beat one and the second bar begins on C again, but now the third of the chord lands on an upbeat. Eight notes fix that. Play the bebop dominant scale in eighths from any chord tone and the root, third, fifth and flat seventh keep landing on the beat, bar after bar.

That is the whole design. The scale was described by David Baker in the 1970s as a way of writing down what Charlie Parker and Dizzy Gillespie were already doing, and the added note is a piece of rhythmic engineering rather than a colour. It is a passing note and it behaves like one: run through it, do not stop on it.

Where it goes in a line

The bebop dominant scale is most useful descending from the root: C B B♭ A G F E D, then C again on the next downbeat. Both sevenths sit between the root and the sixth, so the line drops through the chromatic pair on the way down and arrives on the fifth or third exactly where the ear expects it.

Ascending, the same pair works as a chromatic approach to the octave. What does not work is treating the natural seventh as a chord tone: held over a dominant seventh chord it fights the flat seventh a semitone below it. On a C7, sit on the B and the chord stops being a C7.

The chord underneath

Dominant seventh chords are where the scale belongs — C7, and by extension the whole of a ii–V–I in F. Over the ii chord, Gm7, the same eight notes still fit, because Gm7 and C7 share a key; players who think in one scale per bar and players who think in one scale per two bars end up in the same place here.

It also covers a blues in C for the whole first four bars. That is one reason the scale is taught early: a single fingering carries a beginner through more of a jazz blues than any seven-note scale does.

On guitar

Guitarists usually meet the bebop dominant scale as a Mixolydian shape with one note added on the string where the flat seventh already sits. In the fifth position for C, the added B falls a fret below the C on the second string and a fret below the C on the fifth string, which is a short stretch and no shift.

The practical exercise is not the scale but the enclosure it enables: approach a chord tone from a fret above and a fret below, using the added note as one half of the pair. That is the sound of the style far more than running the scale up and down.

The other three bebop scales

Bebop scales are a small family of four, and all four are built the same way: a seven-note mode plus one chromatic passing note, chosen so that the chord tones fall on downbeats. Bebop major adds a sharp fifth to the major scale, bebop Dorian adds a natural seventh to Dorian, and bebop minor adds a natural third.

Naming is the messy part. Books disagree about which minor scale gets which label, and the same eight notes appear in print under two names. Here each page is named by its note content, which is the part that never changes.

Frequently asked questions