Music Composition App

hey man, i use Music Studio 2 myself... it does what you want and there are some quality sounds in it, although you may have to buy some more in-app for the more symphonic ones.

it's pricey, but if you'll use it, it'll pay itself back. you'll be surprised for how much you can do with it.

me, i don't find myself really using it, but it's not because of the app's quality or ease of use - using a phone to sequence your ideas just doesn't work intuitively enough for me. hope it works for you though.