There is no such word. It sounds to me like pop folk, you can hear a lot of things there. Anyway, I have no idea what the author wanted to express, but it could be a name, who knows. Althought, I never heard such name, except the fashion house Yasha, located in my town. :)) Most likely Georgi is right, it is just a shout.

Sorry Dave :(. I wouldn't want to disappoint you :( ...... but there is no such word in bulgarian. I suppose it's simply a shout ( though I never heard such before) :)