So the singers
shiyr (sheer)
to sing -- sing(-er, -ing man, -ing woman).
Heman
Heyman (hay-mawn')
faithful; Heman, the name of at least two Israelites -- Heman.
Asaph
Acaph (aw-sawf')
collector; Asaph, the name of three Israelites, and of the family of the first -- Asaph.
and Ethan
'Eythan (ay-thawn')
permanent; Ethan, the name of four Israelites -- Ethan.
were appointed to sound
shama` (shaw-mah')
to hear intelligently (often with implication of attention, obedience, etc.; causatively, to tell, etc.)
with cymbals
mtseleth (mets-ay'-leth)
(only dual) double tinklers, i.e. cymbals -- cymbals.
of brass
nchosheth (nekh-o'-sheth)
copper, hence, something made of that metal, i.e. coin, a fetter; figuratively, base (as compared with gold or silver)