This script will apply user-entered text to the "Category" tag of each of the selected tracks. iTunes 5 or better.
(Note: In order to launch this PowerPC-era script on an Intel machine, it must first be opened and then saved using AppleScript Editor, which is located in your /Applications/Utilities/ folder. More information is here.)
Stop iTunes after current track is finished playing
Create a playlist of random Artists and set number of random songs back-to-back
Export artwork of selected tracks to parent or specified folder
Rename selected tracks' Song Names with their filenames (minus extension)
Play the selected track and stop
Play through each track in a playlist at your set interval