I don't know if it is possible to do a very good job of filling you in on Islamic/Middle Eastern Music in a short space, but rest assured, there is a lot of it--the musical traditions are strong, and very long. Of course, their are many cultures in the Middle East, and many more in Islam, each with it's own classical, folk, and pop music--

I don't know a lot about Afghani music, but what I have heard is wonderful--it combines the melodic qualities of Turkish/Arabic/Persian music with the fluid and elastic feel of Indian music--Because it is a primarily tribal culture, music and dance play an important role in both socializing, and transmitting news and information--the ballad tradition is definitely alive, and even as we speak, many Afghanis are getting their only news about the war from songs--

As to Middle Eastern Music in general, it is rooted in Turkish Classical music, even the music in clubs and in the movies--The top performers are as well known as pop stars in the West. and perhaps even more important--unlike in the West, performers are regarded as one of most important vehicles for the culture--The icons include Um Kholtoum(legendary singer, sort of the Ella Fitzgerald/Aretha Franklin), Farid Al-Atrash(Singer/songwriter/Oud player, sort of the Elvis/Dylan/Clapton), and Mohammed Abdel Wahab(, performer/composer who created the modern sound, sort of the Duke Ellington). (Spellings are arbitrary)