Chords in the key of Bb minor on cavaquinho
The key of Bb minor has seven diatonic chords: BbmBbmBbmBbm, C°, Db, EbmEbmEbmEbm, FmFmFmFm, Gb and Ab. As sevenths: Bbm7Bbm7Bbm7Bbm7, Cm7b5, Dbmaj7Dbmaj7Dbmaj7Dbmaj7, Ebm7Ebm7Ebm7Ebm7, Fm7Fm7Fm7Fm7, Gbmaj7Gbmaj7Gbmaj7Gbmaj7 and Ab7Ab7Ab7Ab7. They come from the Bb natural minor scale, Bb, C, Db, Eb, F, Gb and Ab, one on each note. On cavaquinho, the shapes below are the seventh chords of every degree, and the tonic one has F in the bass.
On the cavaquinho, four steel strings tuned D–G–B–D pack the chord into a small, bright space — every finger counts. Its four steel strings give a bright, sharp attack that cuts through the mix and drives the beat.
Seventh chords in Bb minor on cavaquinho
These are the chords of the natural minor scale. In practice the v often becomes V (major) or V7, borrowed from the harmonic minor, to create the leading tone that pulls back to the tonic.