Will Time Machine backup an iTunes library that's stored on an external HD? As part of a family 'computer shuffle/switcheroo' I'm thinking of repurposing a Mac Mini as a media-server running iTunes (to feed our library of video content to our Apple TVs). However, I will need to store the iTunes library on an external hard drive since the Mac Mini has only a 500GB internal drive and the iTunes library currently exceeds 1TB.

Obviously I would want the iTunes library backed up; all our family computers are backed up to a single 3TB Time Capsule. My concern is whether or not the external drive with the iTunes library would get backed up; AFAIK external drives do not get backed up via Time Machine (am I correct about that?), but I wondered if the the linkage between the iTunes app (residing on the Mac Mini) and its library (on the external) would maybe provide a bridge that would allow the iTunes library to be included in the backup.

Can anyone advise? Thanks.
Yes, Time Machine will backup external drives as well. Just make sure that the drive is not excluded in the settings:

System Preferences > Time Machine > Options…