Setembro

Setembro in A#

Key of A#

A# (Bb) major requires barre chords rooted at fret 1 on the A string or fret 6 on the E string. Despite the barre demands, it is a common key in funk, New Orleans R&B, and brass band music. The open D string can ring as the major third for added color. A# is a intermediate-level key on guitar because the open D string is the major 3rd of Bb, adding a bright color if allowed to ring. Expect to rely on barre chords throughout, which builds hand strength and unlocks the entire fretboard.

Voice Leading

The bass line moves through A# to F (descending perfect fourth), F to G (ascending whole step), G to G (ascending unison), G to D# (descending major third), D# to A# (descending perfect fourth), A# to C (ascending whole step), C to C (ascending unison), C to A (descending minor third), A to D (ascending perfect fourth), D to G (ascending perfect fourth), G to D (descending perfect fourth), D to E (ascending whole step), E to E (ascending unison), E to F# (ascending whole step), F# to B (ascending perfect fourth), B to E (ascending perfect fourth), E to B (descending perfect fourth), B to C# (ascending whole step), C# to C# (ascending unison), C# to D# (ascending whole step), D# to G# (ascending perfect fourth), G# to C# (ascending perfect fourth), C# to F (ascending major third), F to A# (ascending perfect fourth), A# to D# (ascending perfect fourth), D# to G# (ascending perfect fourth), G# to C# (ascending perfect fourth), C# to F# (ascending perfect fourth), F# to F# (ascending unison), F# to B (ascending perfect fourth), B to B (ascending unison), B to G# (descending minor third), G# to C# (ascending perfect fourth), C# to G (ascending tritone), G to C (ascending perfect fourth), C to F (ascending perfect fourth), F to F (ascending unison), F to A# (ascending perfect fourth), A# to F (descending perfect fourth), F to A# (ascending perfect fourth), A# to A# (ascending unison). The root motion by larger intervals (fourths and fifths) gives each chord change a strong, decisive character. When the progression loops, the bass returns from A# to A# by unison.

Scales for Improvisation

A# major pentatonic works because every note is either a chord tone or a safe passing tone — there are no avoid notes. For soloing, this means you can play freely without clashing. Over dominant seventh chords, A# Mixolydian adds the flat seventh for an authentic blues-rock edge.