A# Major 6th (A#6)
Also written as Bb Major 6th (Bb and A# are the same key).
Notes in A# Major 6th
Inversions
Same notes as A# Major 6th, with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
A# in the bass
1st inversion
D in the bass
2nd inversion
E# in the bass
3rd inversion
G in the bass
Open voicings
A close-position chord like A# Major 6th 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
E# on the bottom
Drop 3
D on the bottom
Press A#, D, E# and G together on the keyboard and you're playing A# Major 6th.
A major triad with a sixth on top has a warm, slightly old-fashioned charm that was everywhere in swing-era jazz and still turns up whenever a song wants to land on a major chord without the sharper pull of a seventh. It shares three notes with the relative minor's seventh chord, so train your ear to catch the difference.