Nabal
The nabal is a long, straight brass horn that is used in the traditional music of Korea. As the musical instrument has no valves or finger holes, the musical instrument is not a melodic instrument but instead, it plays a single unremitting tone. The exact frequency of the tone that is manufactured can be quite dissimilar reliant on the size of the individual musical instrument.
The musical instrument has historically been used mainly in the military procession music known as daechwita, and also in nongak, to signal the starting and ending of performances.