Final answer:
The four main vocal fachs for male singers are Tenor, Baritone, Bass, and Countertenor, which categorize their vocal range from highest to lowest.
Step-by-step explanation:
The four main classifications of vocal fachs are Tenor, Baritone, Bass, and Countertenor. These classifications are used to identify a singer's vocal range and the roles they are most suited for in operatic and choral music. The Tenor voice is the highest male vocal range, followed by the Baritone with a range in between Tenor and Bass. The Bass is the lowest male voice. The Countertenor, less common, is a male voice that is roughly equivalent to a female Alto or Mezzo-Soprano.