Instrumentology     If the study of the musical culture of a region, both instrumental and vocal music happens alongside with the familiarity of the instruments on that region, it would definitely improve our knowledge about the musical culture, history and the process of the musical completion of that region. Now, we will deal with the existent instruments in Lorestan.   According to Horn Bastel and Zax, the existent instruments in Lorestan place in three out of four categories. These four categories are :Aedephones, Aeropones, Chordophones and Membranophones. Aedophones are those instrument that the instrument’s material itself makes the sound. Aerophones belong to the blowing instruments. Chordophones are the stringed instruments,that are divided into two main categories as Mezrabi and Arshe-i. The last part are Membraphones. They are instruments that are covered by skin and used by beating on them.     The categorized instruments in Lorestan are as shown below:   Aerophones: Sorna, Dozale and Bleour(flute)   Chordophones: Kamanche, Tnbour   Membraphones: Tonbak, Dohol