I planned to use this as a simple portable device for finding notes and melodies for song training, which it can do just fine. I didn't expect it to have the tonal quality for creating music.
But I was surprised how funny it is to express dynamics with your breath and still being able to use your keyboard skills. Note, however, that the name "melodica" is apt. It is great for melodies, but useless for harmonies. One tone at a time, or you will never know which tone in the chord will steal all the air.