Ok so i wanted to take all my music of my powerbook b/c it was getting mighty slow, so i saved it all to my external hoping i could set up it tunes to just play off of the external. so i went into preferences and in the advanced section i change the itunes music folder to the music folder saved on my external. i then closed itunes and reopen it to find that only approximatly 1/3-1/2 of my music is now playable, the rest of the tracks have an exclamation point in the far left column, and when i attempt to play them i get the message that the track cannot be played because the original file cannot be located. any ideas what i did wrong or what i can do to remedy the problem and have all my music playable. thanks in advance!