Apparently you can only add musicians/instruments per album. But on very many albums, the musicians/instruments vary from track to track. Can it be that CLZ doesn’t make it possible to capture this information?
As far as I’ve found, only as a text field, not from the musicians or artists lists.
CLZ Music Web does not have an “edit track” feature where you can dive deep into the track and put all those musicians/instruments per track. I see your request, but right now it is not planned to make this happen I’m afraid.