How do I configure a Smart Playlist to show songs not in other Playlists?

I have a ton of songs that I classify in named playlists, and would like to have an easier way of knowing if a song has been previously classified or not. The thought occurred to me to make a Smart Playlist that will show me songs that meet the following requirements:

• Media Type must be Music (excludes Music Videos, Movies, TV Shows, Books, Podcasts, etc.)
• Must not exist in any playlist within the parent Classification folder.
• Must not exist in the "Unclassifiable" folder.

I can't get the Smart Playlist to populate with all remaining songs:

Is it possible to create a Smart Playlist showing all songs not in another playlist?

Solution 1:

It turns out that the screenshot, or at least the correct version, is sufficient:

No doubt in part to my tens of thousands of songs, and only a few hundreds currently classified, the playlist took sometime to populate. After reading Kyle's comment, I looked at the playlist and nearly my whole library is now present.

So the answer to this problem can only logically be:

Patience