Demetrius Cantemir was formed as much in the Turkish court as in the Orthodox Patriarchate. The Istanbul Cantemir collection and the discovered Tehran collection resemble one another to a significant degree, from content to style of writing. Both contain an astonishingly large number of compositions: around 310 pesrevs and around 40 sema is. The older of the two collections in the Kevseri codex invites comparison with the Melli collection in Tehran and the Cantemir collection in Istanbul. In the Cantemir collection on only two occasions do two melodies in the same maqam follow one another directly. The sema i compositions appear in the Cantemir collection, as already mentioned, as a self-contained block between the pesrev pieces, apart from a few scattered items. It was a suitable and appropriate development of the traditional notation system, known since the thirteenth century, and adapted to local Turkish requirements.