On tonight's show I discussed the mawwal, an improvised, solo vocal piece found in Arabic music. Here's an example of an Iraqi boy singing a mawwal:

As early as the 9th century the mawwal was described in connection with the working class and is composed in colloquial Arabic. The mawwal usually follows a layali, a vocal form whose text consists of the words "ya layali, ya 'ayni" (oh my night, oh my eye), a poetic metaphor to a female. The predominating theme of a mawwal is love and the overall rhythmic concept is free.