C Blues: |C7 |C7 |C7 |C7 |F7 |F7 |C7 | C7 |G7 |F7 | C7 | C7 |
It's a great scale for a one-size-fits-all approach, but leaves out a few excellent note choices like the major third and sixth (E and A in the key of C) which can make your solo a heck of a lot more interesting and melodic. If you add these notes, you'll need to pay attention to the changes, however.
That E won't sound so great when you go to the IV7 chord in measure 5 (F7 in C blues) because of the Eb in the chord. Changing to an Eb during those two measures will make you sound like you know what you're doing. By the same token, adding a B natural (major 3rd in G) in measure 9 for the V7 (G7) chord will give your solo some movement as well.
Beginners, try these ideas out the next time you're improvising. The idea is to use a different note or two when the chords change to go with the harmonic movement. The more complex the song form, the harder it is to keep up. there are some tricks to "playing through changes," too. More about that later.