It's really helpful when you're by yourself. Clip the microphone to your drone or chanter, plug it into the tuner and play. You can see the needle while you're blowing and tell in an instant whether your drone or chanter is properly tuned. I often do this after I've tuned the drones by ear, to be sure I've done it accurately. Another plus: since it's set up for the true bagpipe scale, it's easy to use..