I asked this question in the Suggested Features part of this Forum several days ago. Currrently, you can mark a whole album as in your collection or not, but not individual tracks of an album. OrangeCD needs the latter option, too, in this day and age of single track downloads.

What I do as a not very elegant workaround is to list all the tracks of all albums in Orange, but set the Composer field in track properties to Missing for those tracks that I don't have. I would prefer something more appropriate in a revision.