Answer: basses

AnswerCrossword Clue
BASSESFour-string guitars
BASSESQuarters of many quartets
BASSESAs singers, they get on swimmingly in a school (6)
BASSESString section members
BASSESBack row of many a choir
BASSESPaul McCartney plays them
BASSESQuarters of quartets
BASSESSome choir voices
BASSESParts of many quartets
BASSESLow men in the choir
BASSESLow-key performers?
BASSESThe back of the choir?
BASSESHeavy strings
BASSESChoir section
BASSESOnes playing things low-key?
BASSESThe lowest of the low
bassesof the lowest pitch
bassesany of numerous edible, spiny fishes
bassesthe lowest pitch in music
bassessinger with this voice
bassesthe lowest male singing voice
bassesBASS, the lowest part in music
BASSESChoral contingent
BASSESChoir members
BASSESDeep voices
BASSESOperatic villains, often
BASSESLow strings
BASSESLow parts
BASSESChorus section
BASSESLow voices
BASSESLowest choral parts
BASSESChorus voices
BASSESSome guitars
BASSESLow voiced singers
BASSESQuarters of some quartets
BASSESCello's big brothers
BASSESSome barbershop quartet members
BASSESPinza, Kipnis, Baccaloni, etc.
BASSESChoir members.
BASSESDeep tones.