I have found this scale, quite useful as a basic form of improvisation the A blues scale is A Cnatural   D Dsharp E G natural.When played against an A MAJOR chord. It is apparantly also sometimes called the bluegrass scale, when played against a c major chord..In a twelve bar blues the pattern is repeated for the sub dominant in this particular case d major using D as your starting note for the pattern, and then again for the dominant starting on E and using a patternof E G nat A ASHARP B AND D natural.I was denied the oppurtunity to discuss this fully on another forum so would appreciate any informed comment.