Eb Quartal (So What) (Eb quartal)
Also written as D# Quartal (So What) (D# and Eb are the same key).
Notes in Eb Quartal (So What)
Inversions
Same notes as Eb Quartal (So What), with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
D# in the bass
1st inversion
G# in the bass (Eb quartal/G#)
2nd inversion
C# in the bass (Eb quartal/C#)
3rd inversion
E# in the bass (Eb quartal/E#)
4th inversion
A# in the bass (Eb quartal/A#)
Open voicings
A close-position chord like Eb Quartal (So What) can sound cluttered in the middle of the keyboard. Jazz players open it up by dropping one note down an octave, spreading the same notes wider without changing the chord.
Drop 2
D# on the bottom
Drop 3
C# on the bottom
The notes D#, G#, C#, E# and A# make up Eb Quartal (So What).
Built in fourths instead of thirds, the voicing Miles Davis made famous on So What. It sounds open and modal rather than major or minor, which is why modal jazz and modern comping use it for vamps that stay on one chord a long time.