The five major types of musical instruments are percussion, woodwind, string, brass and keyboard. There are 6 main categories of musical instruments today within the world and almost 300 in each and there are more than 1500 instruments. The main instrument category using and popular all over the world is percussion instruments. A musical instrument is a device created or adapted to make musical sounds. In principle, any object that produces sound can be considered a musical instrument—it is through purpose that the object becomes a musical instrument. Find musical instruments for sale here.