Notice how almost every phrase of this melody ends on beat one (or the and-of-four, but that's just anticipating beat one)
When I started improvising, I treated beat one as the start of my lines. But the great blues players treat beat one as the destination.
Check it out here on Autumn Leaves too...
And Blue Bossa too...
...where each phrase of the melody is driving you into beat one.
Anyway, back to the blues.
Here's the bit that surprised me most. The chord tone you aim for on beat one doesn't have to come from the blues scale. In fact, it's better when it doesn't.
If you only use notes from the blues scale, then you can't tell the difference between the chords. But, when you land on a chord tone, the root, third, fifth, or seventh, the line itself outlines the chord, so a listener can hear the implied harmony, even without anyone playing the chords.
The third of each chord is especially strong at defining the harmony, like you see often in the Autumn Leaves and Blue Bossa examples.
Bad, Noodly Example:
Now, let's compare this to the kind of bad "noodley" line that old Josh would have played. Notice how all the blues scale notes work fine over the chords, but the lines feel like they don't have any direction.
Better, Less Noodly Example:
And here's almost the same line, but with the rhythms shifted forward so the target notes land on the beat. And in a couple cases, I aimed for the 3rds of the chords instead of blues scale notes.