Songs randomly appear gray with iCloud icon?

I have an iPhone 4s running iOS 7 (most recent update) and I have been having some trouble with music.

When I go into the music app, some songs appear grayed out and have a little 'download from iCloud' icon next to it. These appear randomly. (I might have a playable song one minute, and the next minute it will be grayed out.) I only have about 180 songs on my phone and about 2 GB left of storage. I have to click the download from iCloud icon and wait until I can play the song again. Does anyone have an idea on how I can stop this? I really don't want songs stored in the Cloud, I want the songs backed up in the Cloud but I still want the ability to play the songs without having to download them time after time! Any solution is greatly appreciated! Thank you!