Tran Quang Hai tried to sing the whole melody of “Amazing Grace” with overtones in one breath . This will take a little time of training to do so .

Tran Quang Hai sings “AMAZING GRACE” with overtones in one breath . It is rather difficult because the tempo is slow and the performer has to control the pitch of different overtones. Filmed by Bach Yen, Thursday August 27, 2009 in Limeil Brevannes, France