Sorry, which theme do you refer to? (CD#, track#) I always thought that David's theme was the one in "Hide and Seek", and that one is on the OST. However, the A.I. promo is worth getting, if only for those brilliant moments like the Strauß quote in #5 "Rouge City", or the complete "The Moon Rising", or the orchestral Blue Fairy music at the end of disc 2, or this gorgeous oboe melody in CD1 #8: (click to listen) -Chris