ACDEG

ACDEG is a five-note pitch collection commonly identified with the A minor pentatonic scale. The notes are A, C, D, E, and G. This scale can be derived from the natural minor scale of A by omitting the second and sixth degrees (B and F), resulting in the intervals 1, b3, 4, 5, b7 relative to the root A.

ACDEG is also the same set of pitch classes as the C major pentatonic scale (C, D, E, G, A), just with a different tonal center. It is thus the relative minor of C major pentatonic. The lack of semitones within the scale gives it a smooth, versatile sound that is widely used in various musical contexts.

In practice, the A minor pentatonic is popular for improvisation in blues, rock, and folk music. It offers consonant melodies over a range of chords, including Am, Dm, Em, and blues progressions that use E7. Musicians commonly learn multiple five-note patterns across the instrument’s range and connect them for improvisation and riff construction.

The concept is foundational in music theory for pentatonic scales and is often introduced to beginners due to its simplicity and flexibility. ACDEG, as a pitch collection, can be transposed to other roots while preserving its characteristic sound.