I want to feel what I am doing.
When we write phrases, we can read these sentences and hear them in our heads. We then know if they sound good or not.
How do we do that when we write code ? Live coding is what we need to bring the output as close as possible to the typing hands.
Use Lucidity editor or any text editor you like. When you save, we take care of injecting the new code inside the running application.
When you view the source code inside the editor, you can use the mouse to tweak any literal number. Just clic and drag to alter a value and evaluate if the result feels good or not (picture and idea by Bret Victor).
Using standards in the music industry such as OSC, MIDI and HUI MIDI, it is very easy to plug a controller and start using it to control your application. Use a wiimote and act like a god.