The Key of F, from the Bass

F major harmonises to F – Gm – Am – Bb – C – Dm – E°; F minor to Fm – G° – Ab – Bbm – Cm – Db – Eb. A son in this key mostly alternates the tonic and the dominant; a ranchera adds the subdominant; a bolero reaches for the submediant and the supertonic on its way home.

This instrument is the whole bass section by itself — six heavy strings on a fretless neck, roots and fifths on the strong beats and an approach into the cadence, nearly every note doubled at the octave. Almost none of a chord is playable down here and almost none of it is wanted — the ensemble hears the bottom note as the chord, so what matters below is which tone of it gets chosen and which octave it is doubled in. There is nobody to play it in unison with, which is the one section that answers to itself.

Learn the tonic, subdominant and dominant in F until the hand goes there unasked, and the repertoire in this key is largely playable before anybody names a form.