How can I see previously stored tunes no longer on my computer? Where are iCloud audio files?

Question

Maybe my question has an answer too "obvious" for me to see it.  But lately I've become aware of tunes that, for one reason or another, are not showing in my iMac's iTunes program. I went to System Preferences and clicked on "iCloud."  Immediately, I saw how to check iCloud for the following files and documents: Mail, Contacts, Calendar, Notes, Safari (not sure what this category could be for--seeing what was on the web at some prior point in history?), Photo Stream, Documents & Data, Back to My Mac, Find My Mac.
In other words, going to iCloud appears to reveal categories for all of your iCloud content EXCEPT your music files.  I know about iTunes Match, and I think I like it, now that I've gotten used to a few of its quirks.  But certainly there are times when the owner of downloaded, commercial audio files (i.e. Tunes) will not have them on his computer.  And certainly there must be a way for me to see what I've previously stored in the Cloud--if only to remind myself of the music I've purchased and have available to me.
I may be missing something about the whole iCloud concept.  Is there a way for me to see tunes I've previously stored in the iCloud but no longer have on my computer?  (I'm always careful not to delete tunes from my iTunes program unless I see 2 or more identical files appearing on my computer).
Thanks for any directions to the iCloud musical holdings / archives--or clarification of any misunderstandings.
Cap
(I see that I'm currently running OS 10.8.2.  I have only 500 gigs of memory, and my music collection is so larg, I'm almost dependent on being able to access songs in the iCloud.  Next time, I'll certainly pony up for the largest memory Apple offers on an iMac.)

Answer 1

They are not showing up in Lightroom at all. I already deleted them.
When I try to import them again into Lightroom it wants to add another 2012 folder to wherever I am trying to insert them and then it does the month/day folder when it already has the month folder it should automatically go into and not be adding a seperate 2012 folder first.
I can't even get it to do the above right now. Now all it does is it wants to make this seperate 2012 folder with the month/day folders but has little boxes beside each folder showing that there are no images to import. The images do show up on the import screen but they are all darkened and unchecked. When I click the proper folder to import them they come on bright and have little boxes checked, but that lasts for less than a second before it decides they are not new. They are new images, I deleted them all out of Lightroom, and probably missed deleting some through Lightroom but instead deleted them straight from the folder outside of Lightroom. This is what is probably causing me such grief and I have found nothing in my searches to tell me how to correct this. *sigh*