The blues scale

Take the minor pentatonic and add ONE chromatic note between its 4 and 5: the ♭5, the famous BLUE NOTE. Six notes in total.

That single extra note carries the whole blues sound. It wants to slide — into the 5 or back down to the 4 — so treat it as a passing note, not a resting place.

A blues scale: A–C–D–E♭–E–G.

1 · ♭3 · 4 · ♭5 · 5 · ♭7

A blues scale: the minor pentatonic plus the blue note (E♭).

Practise this in the trainer — it opens with this lesson the first time the concept comes up.