Cmaj7, C#dim7, Dm7, G7

Analysis

Heard in C major

Progressions in these changes

• All the chords

  Diminished Passing Turnaround in C

  The I-VI-ii-V with a diminished 7th chord on #I in place of VI7, so the bass rises by half steps from I to ii.

Scales to play

• Over Cmaj7 · Imaj7

  C Ionian

  The major scale and its modes are the most commonly used scales in western music.

• Over C#dim7 · ♯i°7

  C# Altered Diminished

  Mode 7 of Harmonic Minor

• Over Dm7 · ii7

  D Dorian

  Mode 2 of Major

• Over G7 · V7

  G Mixolydian

  Mode 5 of Major