Most of my music is not in iTunes! How do I get it back?

Question

10June2013
I uploaded many music CDs years ago.  I kept servaal ipods full of music. 
I noticed recently that almost all my music is missing from the Itunes music library. 
I update Itunes Match several times a week, I hope to God that my music in in the ICloud. 
However, I want my music in my hard drive.  I also want it in the cloud, but I want my music files on my hard drive.
I have several back ups of my computer that should have most of the music and I can get the rest (the newer CDs) from the cloud (I hope).
What is the best way to get my music back into my Itunes music library using a back up (time machine or carbon copy) or from the cloud. 
I have several of my favorite bands gone from my itunes libary and not on my ipods.   It took a very long time to down load one music band from the icloud.  It wil take weeks to download all my music from the cloud.
It took weeks to load all my CDs onto itunes back in 2005.  I don't want to do that again!   Do any one have a suggestion?
chhenden

Answer 1

Craig
I am finding every single hard drive that has a itunes library on it.  I am only moving the music folders inside the itunes folder to the new WDhd.  After the music folder is on the WDhd, I add what disk it came from. COPY media files (MP3, M4A, etc) whilst noting where they came from
     Do I make a big music folder on WDhd, called "BIG MUSIC Archive" and dump the content of each of the downloaded music folders into the BIG MUSIC Archive? That is what I had/have set up
     Won't there be a problem wiht folder (artists and albums) deleting each other where the last music folder wins? No because you copy them to separate folders/directories initially.
     This is were I am now.
     Later, Step 2,  turn on my usual Itunes and do the Library -> Consolidate     ?
     THis will absorbe the BIG MUSIC Archive on teh WDhd drive.   I wil call my current libary on my current itunes external drive  ORIGINAL MUSIC
     Maybe before STEP 2, I should get rid of all the dead files (a title but no song) that I mentioned before. Dead files can help you track what you cannot find
     I can then use the resutling  ORIGINAL music folder as the new BIG MUSIC folder on my dedicated WDhd Arcihve hard drive. YES OR Allow iTunes to copy to the iTunes folder (Preferences->Advanced Tab.  I never do/did this as my PC Hard Drive partition/Macbook Air does not have the storage space.
     Is that a good paraphrase of what you told me to do?  If not, please give me simple instructions.