Having looked around for solutions, and there seem to be many that work for some and not others, I decided to try the one solution that seemed to work across the board; deleting and reinstalling iTunes. It seems to have done the trick, and iTunes actually seems more responsive.
To delete iTunes I followed the following advice:
Deleting iTunes is not recommended unless you know what youre doing.
Launch Terminal from the Utilities folder within Applications and type the following commands:
cd /Applications/
This brings you into the Applications directory, the next command deletes iTunes itself:
sudo rm -rf iTunes.app/
Enter the Administrator password to confirm. There is no warning or confirmation and iTunes will immediately be deleted, effectively uninstalling it from the Mac.
Deleting the iTunes application will not delete the iTunes library or music, and any purchases bought through iTunes will still remain tied to the Apple ID used to originally buy them.
You can then download the newest version directly from
http://www.apple.com/itunes/download/ and running their installer will bring iTunes back to life on your computer.