Kuajok, Gogrial, Tonj are all Rek group we speak the same dialect, the differences can be realize in pronunciation..  But Agook , Awan (Gogrial)  and those of Kuajok you can not differentiate unless he/she told  you that I am from (Agok/Awan or Kuach..) But if a Twich or Malual man or woman spoke you can know them  immediately.     
The tribe in Kuajok are called Kuach. I failed to record Kuach man song he has gone home, but yesterday I recorded  Agook woman from Gogrial, (her name is Nyanateer Mading)  she sung three songs.