TSM is an abbreviation for Türk sanat müziği, meaning Ottoman classical music in English. It developed in in Istanbul and major Ottoman towns from Skopje to Cairo, from Tabriz to Morocco through the palace, mosques, and sufi lodges of the Ottoman Empire. Above all a vocal music, Ottoman music traditionally accompanies a solo singer with a small instrumental ensemble. In recent times instruments might include tanbur, lutes, tambourine, kithara, ney flute, kemençe fiddle, keman Western violin, kanun zither, or other instruments. Sometimes described as monophonic music, the variety of ornamentation and variation in the ensemble requires the more accurate term heterophonic, with an apparent byzantine influence.