How many guitars does Ani Difranco need for one show?

Whoever has seen folksinger Ani Difranco live knows that they bring her a new guitar for every song because each one needs different tuning. She then must have several prepared before hand, cause I really doubt there’s a guy back there who tunes the same guitar back and forth every three minutes. Besides, a friend of mine who loves to play Ani’s songs told me the way she tunes her guitar is insane (in a good way). In any case, she’s a great live performer, if you get the chance.