The chart below lists the common chords in the key of E flat major. The first row are triads and four note voicings are in the second row. Roman numerals indicate each chords position relative to the scale.
D sharp major
The same chords and scale notes are used for the key of D sharp major but this key isn't used often because of notation difficulties caused by the need for a double sharp. More info on this can be found here in chord theory.
|Common chord progressions in E flat major|
|I - IV - V||Eb - Ab - Bb|
|I - vi - IV - V||Eb - Cm - Ab - Bb|
|ii - V - I||Fm7 - Bb7 - Ebmaj7|