Why is some of my music on my iphone, but not my iTunes on my computer?

On my iPhone, I have a complete album that I've bought. I've had it for a while and the full album was also on my iTunes on my computer but now there are only some songs left of it on my computer. Why did that happen and what can I do to get the full album back on my computer?

Download it online, no one pays for music anymore.

  • Why won't some songs transfer from my iPhone to iTunes on my computer? I've purchased many songs from iTunes on my phone and when I hook my phone up to my computer, most of them sync and are added to my library but some do not, which means when I go to the iTunes Store, it says I haven't purchased those songs when I actually have. Is there anyway to get them to sync onto the computer or should I try emailing Apple?
  • Why is there music on my iphone but not on my itunes? I deleted all of songs on itunes to clear space. But on my iphone music, there are still like 200 songs that I've never even heard of before and I don't know how to delete them because THEY AREN'T ON MY ITUNES! There's the little cloud thing next to these songs but what does that mean.
  • Why is the Wi-Fi connected to computer but not to iphone 4? I have been having trouble connecting to iphone. My wireless connects home to Wi-Fi and others but at work it won't connect. It says it connected to computer but on my phone says connected but when i actually go into Wi-Fi it just has a waiting sign going around which won't connect. Does anyone know why this could be?
  • Why is iTunes not syncing some of my music? I have 2 albums of Red Hot Chili Peppers, Dani California and Greatest Hits, and when I sync them to my iPhone, I tap on Red Hot Chili Peppers and it only comes up with Dani California and non of the others appear. Why is it doing this?