There a lot of iPad and iPhone musicians out there and many people use it for making simple and more complex music. An iPad can be used as hardware sequencer but in this hype about IOS, where is Windows 10? There are some applications out which works already great with Microsoft Touch Devices.
At SuperBooth, Bitwig demonstrated me the multi-touch feeling and usage of an Windows tablet. I must say that the touch feeling and usage are now better than before 2 years. Check it out in this video