The scientists are always thrilled when аn instrument is found during some archaeological excavation, especially from prehistory. It changes our perception of prehistoric societies, and it challenges people to find a way how to construct instruments, produce sound, and present this kind of music using reconstructed music instruments. There is a variety of prehistoric music instruments found on archaeological sites around the world, flutes from bones and wood, drums, lithophones, aerophones, and other types of instruments.
In 1989 small globular flute at the Neolithic archaeological site of Mramor (near Veles) was found. This very first prehistoric ocarina-type flute instrument found in Macedonia with a diameter of 4.7 cm and a hollow interior, has an irregular spherical shape and it is made of refined reddish clay. The surface is without any decorative elements, while the object is pierced with three holes with different diameters (0.4 cm and 0.6 cm), arranged like the apexes of a triangle.  There was an attempt for the glass reproduction of the sound by musician Dragan Dautovski, who made live performances a couple of times with the original artifact.
Most of the prehistoric music reconstruction lies in the field of experimental archaeology. There have been many attempts in order for scientists to reconstruct the music and sounds from prehistorical periods. In the video below, we can see the archaeologist Jean-Loup Ringot, Ph.D., who specialized in prehistoric music, and he demonstrates the lithophones. The stone blocks he uses are from chalcedony, and when you chip this kind of raw material, especially with grey color, you will get the well known prehistoric tools that folks knew them as flints. We can just guess that the stones blocks were first chipped and later additionally were grounded in order to provide this kind of bell sound.
Within Kratovo-zletovo paleovulcanic region located between Kumanovo and Kratovo, i.e between the archaeological sites Kokino, Konhuh, and Cocev Kamen (which are made from the same type of rocks by the way) there is an abundance of similar type of raw material, such as chalcedony, agate, opal, etc. 
We can not be sure, we can just presume that this is somehow the music in prehistory should sound of … not only at Kokino, but in the prehistoric communities that lived at Tumba Madzari, Cocev Kamen, and hundreds of other sites around Macedonia.
 Jovcevska, T. 2007, “Globular Flute”. Skopje (in Macedonian)
 Dimitrovska V. 2012, The system of local supply of stone tools in Amzabegovo-Vršnik culture from Neolithic Macedonia, Documenta Praehistorica, XXXIX: 353-360. Ljubljana.
Ms.Sci in prehistory