With this app you can play the music up to 50% slower to learn the difficult passages better. You can also change the key. Thanks to new technology, you can change the tempo without affecting the pitch. And if you change the key, the speed is not affected. With the recorder function of your iOS device, you can let the music teacher play right away and at home play the whole thing at a "leisurely" speed, according to your tempo. If you want to practice a certain sequence, you can easily select the range that will be repeated until you end it with Loop Start and Loop End.