An Interactive MIDI Arpeggiator
Some producers will create music using only whatever tools he or she has available to them. It could be nothing more than a laptop computer (and there’s nothing wrong with that). Take an artist like skrillex, who created an award willing album using nothing but a computer and no peripherals. Aside from using a singular DAW to create music, you also have the option of using aftermarket tools (hardware or software) to add effects to your music that would otherwise be more difficult to do from a purely software approach. And even when you begin using external physical devices with your system you aren’t limited to simple pieces of hardware either.
Take harmonization for example. A guitarist would likely use a hardware stomp box to add harmony effects to his guitar. It makes the most sense because it integrates directly into his system without having to add much more than a piece of hardware. For DAW producers, an iPad app may make more sense as it can employ the same characteristics as a physical stomp box, yet also use midi control and inter-audio properties to their advantage. Arpeggionome is an interactive app that plays with octaves to create such harmonies and shifts, but isn’t limited to a physical box.