Estai (Esmagambetov) Berkimbayuly (1868 as well. Akkol Ekibastuz Pavlodar region - 1946, ibid), singer, bard and composer. Honored Artist of Kazakhstan (1939), one of the first members of the Composers' Union of Kazakhstan (1940).
Acquainted with Birzhan fat, Yestay entered his creative environment. Together with well-known singers and akyns Akan series, Baluan Sholak, Ukili Ybyraem, Satmagambetom, Shashubai and other spoke on the big festivals in Omsk, Kokshetau, Petropavlovsk, Zhaisan, Tarbagatae, Zhetisu.
With his work contributed to the further development of the performing traditions sal, sulfur. Yestay songs "Жай Қоныр", "Наз Қоныр", "Майда Қоныр", "Қорлан", "Сандуғаш", "Жүрен ау", "Ашу пышақ", "Дүние ау", "Еркем", "Гүлнар" "Қоштасу" is the crown jewel of Kazakh music. The song "Қорлан" Yestay name turned into a legend. The melody of the song used in the opera "Birzhan - Sarah" M.Tulebaeva, "Er Targyn" E.Brusilovskogo, the concert and the orchestra for kobyz S.Shabelskogo and L.Shargorodskogo.
For explanation of the song "Қорлан," the poet wrote K.Amanzholov dramatic poem "Қорлығайын" (1939).
In 1939 Yestay Berkimbayuly participate in the second meeting of the Union of Writers of Kazakhstan. During the Great Patriotic War, gives concerts in the population, inspiring them to victory. Musicologist and composer B.Erzakovich recorded his songs on the music. Poet M.Alimbaev dedicated Estai poem "Естай - Қорлан" (1968).