How to remove the pipe with a horn: use a soft hammer or wrap some cloth, knock around the joint a few times and remove it. Horn is a vocal instrument with vibrating lips. When using the instrument, you can use the tuner to check. If the pitch is high, pull out the tube, if the pitch is low, insert the tube a little. Horn is a brass musical instrument, which has a copper spiral tube, a funnel-shaped horn, a big horn, and sometimes it is detachable.