“Whenever your body needs to make a movement, the nervous system sends out tiny electrical signals that control your muscles. The technique of electromyography (EMG) allows us to amplify and measure these electrical signals. In addition to being a useful clinical tool for diagnosing various neurological disorders, EMG recordings can be used for engineering projects such as controlling prosthetic devices or playing music. If you’ve watched the White Rabbit Project, you know that EMG signals can even be used to control someone else’s arm! This Instructable will walk you through the process of building an EMG amplifier that allows you to translate the tiny electrical signals produced by motoneurons into an audio signal played through speakers. These instructions are for making a two channel amplifier (i.e. listen to the activity of two muscles at once), but it’s simple to make a single channel amplifier to save time and/or parts. Let’s get started!”