The traditional Macedonian songs draw from the musical idioms of mainland Greece but are made heterogeneous by influences from neighboring nations and refugees. Macedonian music serves as a link between the traditions of Epirus and Thessaly in central and southern Greece and the music of Thrace and Istanbul, making the study of Greek song evolution difficult without it. The music varies between mountain and southern styles that are more continental, as well as urban areas with strong local characteristics and coastal regions influenced by the East while retaining domestic elements. A wide variety of musical instruments and topics covering all human life events are featured. Thessaloniki also has a unique music history as a major Mediterranean port integrating many traditions.