iTunes 11 introduces a new “Live Search” feature that is designed to allow you to search across your entire iTunes library when entering information in the Search field in the top-right corner of your iTunes window. As useful as this may be for some situations, not everybody will necessarily be a fan of the new search style, particularly as it can be somewhat slower with larger libraries. The good news is that if you find the feature more annoying than useful, you can very easily turn it off: Simply click on the magnifying glass in the search field, and a drop-down menu will appear with an option, enabled by default, to Search entire library.
Click on this option to turn it back off, and iTunes will return to the search behaviour found in previous versions, allowing you to filter only the displayed category rather than showing results from your entire library. As a bonus, you can easily tell which mode is enabled from reading the background text in the search field; the word Search will be followed by Library when the full “live search” is enabled or the current category name (e.g.
“Music”) when using the older style filtered search.