On
piano or
synthesizer keyboard, I like the blues scales on D, E, or A to
improvise on because the black note falls so conveniently under the fourth finger.
D Blues:
D F G G# A C D
E Blues:
E G A A# B D E
A Blues:
A C D D# E G A
The easiest fingering for the right hand is 1 2 3 4 1 2 3.
I would have to disagree with fricto's assertion that the blues scale is based on the minor scale. It is based on the pentatonic scale, a minor pentatonic scale, to be exact, like the 5 black keys on the piano, with the added tone, the augmented fourth, diminished fifth, or tritone: the G#, A#, and D# in my examples above.
It is also known as the diabolus in musica.