Digital Music Distribution Process...

I didn't know where else to ask this question but here goes...

When you buy a song from Amazon Mp3 or iTunes, or listen to Pandora or Rhapsody etc., do you ever wonder exactly where the music comes from & the process involved to get it there?
Does a record company group own a data center then rent the catalog to services like Rhapsody & Pandora, or does each service own its own data center & is thus responsible for creating the music files by ripping cds, or do they purchase digital files in bulk from the record companies?
 
Does anyone know the entire process for getting a song to a digital distribution service after it is recorded & mastered?
 
I found an article on Apple's data center in North Carolina:
[link=http://www.datacenterknowledge.com/archives/2011/06/06/steve-jobs-provides-a-look-inside-the-idatacenter/]http://www.datacenterknow...nside-the-idatacenter/[/link]
but this data center seems to be for user content & not the original source for iTunes' store.
 
It would be cool to create a flow-chart for the entire process.

We have been doing ours through Reverbnation. Check out our page there at http://www.reverbnation.com/wallowsound You can purchase the digital distribution packages (a few to choose from), upload your content to them once & they get it out to however many vendors are included in the package you chose. In our case it took about a month for our album to go live on the big ones like iTunes & Amazon.

Yep we are playing out constantly, Promoting, Social networks, our website, RN page, always trying to drive new people to our music, We get some radio play on the local show on Sunday nights (they played 1 of our songs in regular rotation this morning!), and we are on about 15 different internet radio stations so far getting regular airtime on those. 
  It is hard to keep the ball rolling that is for sure.

I think the package costs us about $35/year. Good to know though.... I may check into it for future releases. Because we have so much done through ReverbNation I suppose we did it that way because it was easy...? haha We also changed our website, I own the domain and had a site I designed their, but ended up changing to one hosted by them because their site is more interactive, visitors have access to our store, music (at the bottom of all pages while viewing the site), videos,more photos & they load way faster than I could get it to, guestbook etc. That runs us about $17/month but it's sooo damn cool! http://www.wallowsound.com