Answer:

bassos

Answer	Crossword Clue
BASSOS	Operatic voices
BASSOS	They're the lowest
BASSOS	Opera villains, often

BASSOS	Low men
BASSOS	Low voices
BASSOS	Kipnis, List, etc.
BASSOS	Pinza, Kipnis, etc.
BASSOS	Opera singers.
BASSOS	Siepi and Vichey.
BASSOS	Singers.
BASSOS	Men of song.

BASSOS	Singers
BASSOS	Hines, Tozzi, etc.
BASSOS	Chaliapin et al.
BASSOS	Hines and Moll
BASSOS	They perform "Asleep in the Deep"
BASSOS	Ones deeply involved in opera?
BASSOS	Choir section
BASSOS	Low singers

BASSOS	Those playing the role of Boris Godunov
BASSOS	Met villains, often
BASSOS	Some "Rigoletto" performers
BASSOS	Some singing villains
BASSOS	Deep-voiced singers
BASSOS	Low-voiced opera singers
BASSOS	Low opera voices
BASSOS	Met set

BASSOS	Low men at La Scala
BASSOS	Some operatic voices
BASSOS	Deep voices
BASSOS	Deep-voiced men
BASSOS	Ezio Pinza et al.
BASSOS	Pinza and Chaliapin
BASSOS	Some Met stars
BASSOS	Samuel Ramey and Ezio Pinza

BASSOS	They often end on a low note
BASSOS	Mozart's Don Alfonso and Leporello
BASSOS	Lowest-voiced choir members