C Dominant 7th (C7)
Notes in C Dominant 7th
Inversions
Same notes as C Dominant 7th, with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
C in the bass
1st inversion
E in the bass
2nd inversion
G in the bass
3rd inversion
Bb in the bass
Open voicings
A close-position chord like C Dominant 7th can sound cluttered in the middle of the keyboard. Jazz players open it up by dropping one note down an octave, spreading the same notes wider without changing the chord.
Drop 2
G on the bottom
Drop 3
E on the bottom
Play C, E, G and Bb together and you get C Dominant 7th.
A major triad with a minor seventh stacked on top, this is the workhorse chord of blues and functional harmony. Hiding between its third and seventh is a tritone, the same restless interval that gives the chord its itchy pull toward whichever chord sits a fifth below.