A minor add9 chord is created by adding a 9th degree to any minor chord. For example, a Cmadd9 chord contains the notes C, Eb, G and D (1, b3, 5 and 9). Here are some common open minor add9 chord shapes.
Cmadd9

Dbmadd9

Dmadd9

Ebmadd9

Emadd9

Bmadd9

F#madd9

Fmadd9

Gmadd9

Abmadd9

Amadd9

Bbmadd9
