From the recording The Fluid Score

Unexpected Zeybek - Tev Stevig
A zeybek is a somewhat slow but muscular dance in 9/4 rhythm from Greece and Anatolia. Stevig set out to write a zeybek for the Trio, but instead arrived at this tune, which is in 11/4 time and not a zeybek at all! That said, it still has the feeling of a zeybek and so the name stuck.