Friends. According to the celebrity website, Meng Ling is not only Liu Hegang's mentor, but also introduced his good friend David Jiang to Liu Hegang. With the help of David Jiang, Liu Hegang's singing skills have been improved more powerfully. David Jiang, 1947,122 was born in Heping District, Tianjin, China tenor, national first-class actor, winner of special allowance from the State Council and member of China Musicians Association.