It was some kind of horn. I think it was the Baroque horn or the baroque trumpet.
The two Donatello's characteristic formal contributions are encountered in the work for Baptistery of Siena. He demonstated it through organizing the relief by a rigorous application of the rules of perspective. Even though it was created at a shallow deptht, this technique makes each figure of a scene emerge clearly and very logically. This technique is determined as a flattened relief.
Closer was written by Halsey, Shaun Frank, Isaac Slade, and Joe King