What I love about this lick is the chord tone pattern in measure 2 that moves down a half step. The first measure starts with a nice chromatic triplet approach which moves us in to the F7 mixolydian scale then we come down and land on the 5th of our E-7. Here we start our chord tone outline with a triplet and move down a half step and repeat the same thing. The reason this works is because we are playing over the tritone of the A7 chord. The tritone would be Eb7. Finally we resolve to the 1 of D-7.