What's the hardest song you've ever heard in the world to sing?

"Lost Rivers" Lost Rivers is also known as Lost Rivers. Performed by Sainkho Namtchylak, the entire album is a vocal experiment, except for "Memory I" and "Memory II," which have distinct melodies and lead lines. The song "Lost Rivers" has no melody or lyrics and is a broken vocal wail from start to finish. Sainkho Namtchylak's vocals are in excellent condition - this is a 1991 studio recording, after all - and Sainkho Namtchylak, who has been called a "vocal extremist," has a number of breathtaking songs to her credit. In addition, she has an excellent range across seven octaves.