Originally Posted By: edshaw
Amin is the relative minor of Cmaj.
AMaj is the 6th of the C scale.
But, what is the A# chord or A# scale relative to CMaj called?
Anyone know?


"A" is the sixth note of a C major scale. But the diatonic chord built from it is an Amin.

The Bb (A#) might be said by a music theorist to be borrowed from another mode of C major. There are 3 modes of C that have a Bb as the VII chord. One is a major mode--Mixolydian. Two are minor modes--Dorian and Aeolian (usually just referred to as "Minor"). As Noel said, what is what would depend on other factors.

As for me, I'd just do what sounds and feels right and leave it to "theorists and theory" to explain what I did. grin It's liberating to know there are options, however, and theory can point the way.

BIAB 2021 Audiophile. Windows 10 64bit. Songwriter, lyricist, composer(?) loving all styles. Some pre-BIAB music from Farfetched Tangmo Band's first CD. https://alonetone.com/tangmo/playlists/close-to-the-ground