In this case that means we have to find the scale that goes with the A7 chord.
And you’ve guessed it : as with any other dominant seventh chord we can play the mixolydian scale on top of it.
And we can play Standard Riffs too!
Note that we’re very close to jazz territory here.
We already have to get the three mixolydian scales in there and this presents another challenge.
Luckily we have the Standard Riffs and all their variations to help us out.