Chord sequence

Dm7, Db7, Cm7, B7

Dm7 D♭7 Cm7 B7

Tempo 120 BPM

Rootless Shells Guide tones Rooted shells Rooted Drop 2

Four-note rootless voicings in their two forms, with the 3rd or the 7th on the bottom, played over the root.

Customize each chord

Dm7
Db7
Cm7
B7

Analysis

Heard in Bb major

Each chord's roman numeral and role in Bb major
Chord	Numeral	Role
Dm7	iii7	Diatonic
D♭7	subV7/ii	Tritone substitute for V7/ii
Cm7	ii7	Subdominant
B7	?	Outside the key (bII7)

Progressions in these changes

All the chords

Chromatic iii-bIII-ii-bII Progression in Bb

The iii-VI-ii-V turnaround with both dominants replaced by tritone substitutes, so the roots descend by half steps from iii to I.

Scales to play