I found a method that works on MacRumors:
1) Rename iTunes.app to something else. (iTunes11.app?) You may have to go into the terminal and "mv" the file to do this.
2) Go to /System/Library/PrivateFrameworks and find a file called CoreFP.framework. Copy it somewhere and rename it CoreFP2.framework
3) Use Pacifist (I've been told you need to use version 3.0.10, the newest one doesn't seem to work right -http://www.charlessoft.com/pacifist_olderversions.html) to install iTunes 10.7 (http://support.apple.com/kb/DL1576?viewlocale=en_US&locale=en_US).
4) Replace your iTunes library if necessary with an earlier 10.7 .itl file.
5) Move the copied CoreFP2.framework file into /System/Library/PrivateFrameworks
6) Make sure none of your devices (iPod/Pad/Phone) are connected and restart your computer.
Once rebooted, go ahead and run your 10.7 iTunes.
Just installing it will overwrite the new CoreFP file, and that will hose your App Store and possibly other functions within Mavricks. Doing this minor surgery keeps both Frameworks installed and places then in a manner that allows the App Store to work while not getting the errors in iTunes 10.7 that would prevent you from using the iTunes store.
