Time Machine backup iTunes purchases only?

[BulkHedd]

The external drive I'm currently using with Time Machine is not large enough to back up everything so I decided to omit my iTunes library from the backup.
The most important thing in that library are my purchased tracks. Is there a way to set Time Machine to only back up the iTunes purchases, along with the rest of my data?

 

[apfhex]

Put you non-iTunes-purchased music in a separate directory, exclude that directory from being backed up.