What is "pesrev"

Peşrev (pronounced in Turkish), Pişrev , peshrev, or pishrev; called bashraf بشرف in Arabic; is an instrumental form in Turkish classical music. It is the name of the first piece of music played during a group performance called a fasıl . It also serves as the penultimate piece of the Mevlevi ayini, ritual music of the Mevlevi order, under the name son peşrev (final peşrev), preceding son semai. It usually uses long rhythm cycles, stretching over many measures as opposed to the simpler usul the other major form of instrumental music uses, saz semai.

Along with the saz semai (called sama'i in Arabic), it was introduced into Arabic music in the 19th century, and became particularly popular in Egypt.