Cronos
Lemmy
Araya
He means vocalists with bassy voices. Not vocalists who also play bass. Don't feel bad because I almost answered some of the same, hahaha.
This is purely a joke and I admittedly had to look up the guys name (taking some of the cleverness out of the humor), but what about Brad Roberts from Crash Test Dummies?
Ville Laihiala (Charon, Poisonblack)