based on A#

or Bb

Tuning 6 5 4 3 2 1
Bb F Bb D F Bb C
Bb F Bb D F Bb D
Bb F Bb C F C D
Bb F Bb C F Bb D
Bb D A D F Bb F is this really Bb?
Bb F Bb D F A D
Bb Eb Bb C F C D