1 Chronicles 15:15 (KJV)

For because ye did it not at the first, the Lord our God made a breach upon us, for that we sought him not after the due order.

So the priests and the Levites sanctified themselves to bring up the ark of the Lord God of Israel.

And the children of the Levites bare the ark of God upon their shoulders with the staves thereon, as Moses commanded according to the word of the Lord.

And David spake to the chief of the Levites to appoint their brethren to be the singers with instruments of musick, psalteries and harps and cymbals, sounding, by lifting up the voice with joy.

So the Levites appointed Heman the son of Joel; and of his brethren, Asaph the son of Berechiah; and of the sons of Merari their brethren, Ethan the son of Kushaiah;