How to find low bitrate audio (non alac/flac) I'm relatively new to the audiophile world and I still have some lossy audio files in my music folder. I do have all this music on cd so I would like to find the lossy albums so that I can rerip these, but this time in alac. How can I do this?

A smart folder works, but shows each track individually so that identifying each album still takes up quite a bit of time. I've tried a couple of disk usage tools, but none of them were capable of filtering by filetype or even better by audio bitrate.

Is there software out there that can do this? An iTunes script perhaps? Any help with sieving through a 300gB collection will be much appreciated.
In iTunes, go to the menu View -> View Options.

Expand the File triangle, and check “Kind”

You can now sort your songs by file type by clicking on that column header, and they cluster by album.

Alternately, make a smart playlist that includes files by their kind or size, and use the View dropdown in the top right to view it by Artist List (or Grid, but I assume you have your music collection sorted by artist.)