Run! don't walk to your nearest App store and download GarageBand. It is now available for free with iOS7 devices. That iPad in your hands is about to become a musical playground. When I first got this app for iPad I was completely amazed that it could do what it did and only cost me $4.99. Now you will not have to suffer the loss of nearly $5 to have this app for your very own.
This post will not go through all the features of GarageBand, suffice to say that once you download it just start playing and exploring. I think you will be impressed.