So far, our app is essentially a tuning fork. Let’s turn it into an actual guitar tuner that picks up sounds from your guitar and lets you know how far you are from the desired pitch. This will require an object that we haven’t seen yet, fiddle~. It takes an audio stream and extracts a number of useful features from it, most importantly the dominant pitch, which it sends to its left outlet as a MIDI note value (Figure 5-6).

You can try this in Pd; just open the patch and sing or whistle into the microphone, and you should see note values in the number box that's attached to the fiddle~ object. Update the zip file containing your patch and don’t forget to refresh your project to make Eclipse aware of the change.