For many people, the iPhone’s best use in a muscial context is as a track-starter - something to come up with ideas on when you’re out and about. So, we get apps like Fortamento.
Unlike some musical sketch pads, the focus here isn’t on beats. Instead, you can create 4-bar chord progressions and add melodies over the top of them. Obviously, you can choose your chords, and there are various instrument sounds.
There’s no suggestion that this is an app to create full songs with: once you’ve got something you like, you can export it as a MIDI file and load it into a DAW so that it can be developed.
Fortamento is available now from the Apple App Store. It costs $4.99/£4.99.