Solo 2 starts off with a sequence that incorporates approach notes like the one we’ve seen in solo 1, bars 8 and 9.
It features blues position 5 between these two C chords:
The mixolydian scale that’s being used is right beneath our fingertips.
And on the F7 we’re playing chord tones, that sound very sharp.
That’s because the interval we are playing is a tritone (aka “the devil’s interval”).
On the G7 chord we’re playing another favorite of Charlie Christian.
Try to see the G9 arpeggio in it and the mixolydian scale above that.
The riff is completed by adding chromatic approach notes.