YLT
(i)
 5  and four thousand gatekeepers, and four thousand giving praise to Jehovah, `with instruments that I made for praising,' 
saith David. 
 6  And David distributeth them into courses: Of the sons of Levi: of Gershon, Kohath, and Merari. 
 
7  Of the Gershonite: Laadan and Shimei.