Learn to play the trombone and improve on rhythm and pitch. tonestro listens to you while you play the trombone and gives you immediate live-feedback on rhythm and pitch. A tuner lets you tune your trombone easily. tonestro for Trombone offers a large collection of songs, exercises and guided lessons for every skill level. Learn how to read music notes and improve your trombone skills by playing many songs and exercises. With the tuner you tune your trombone fast and easily for perfect pitch.