The D9 chord (dominant 9th): notes D F# A C E, degrees 1 – 3 – 5 – ♭7 – 9. Guitar shapes: x52532, x5455x, 10-7-7-7-7-8, 10-9-10-9-10-x.
A chord is the root plus degrees above it, most often stacked in thirds. Major and minor differ only in the lower third: a major third (M3) sounds bright, a minor third (m3) sounds sad. Pick a chord and a root to see its degrees and intervals, and its shapes.
m — minor, M — major, P — perfect, A — augmented interval; the number is the degree count. m3 is 3 semitones, M3 is 4, P5 is 7
D Dm D5 D7 Dm7 Dmaj7 Dsus2 Dsus4 Dadd9 D6 Dm6 D9 Ddim Ddim7 Dm7♭5 Daug