A sharp/ B flat major piano scale. From the Root note A#, we create the A# piano major chord. Then using the piano formula for major scales- RWWHWWWH (R for root note, W for whole step and H for half step), we create our A# major scale.
From the above diagram, piano notes A#, D and F when struck together creates the A# major piano chord. Then applying the piano major scales formula, we get the following notes depicted in the below diagram: A#,C,D, D#, E, F, G,A,and A# again. This is what is termed as A# piano major scale.
Note that the A sharp major scale notes are the same as the same as the B flat major scales notes. And the B flat major piano chord is the same as the A sharp major chord as depicted below.