Final answer:
In opera, powerful, mythical, or evil characters are typically played by singers with bass or baritone voices. These deep and resonant voices are well-suited to portray the gravitas these roles often demand. This practice has historic roots in theater, where costume and voice amplified the portrayal of different characters.
Step-by-step explanation:
Throughout the history of opera, the type of voice that typically performs the role of a powerful, mythical, or evil character is usually a bass or a baritone. These voice types are often cast in roles that project authority, strength, or villainy. This tradition is rooted in the deep, resonant quality of these voices, which can effectively convey the gravitas and menace required for such characters.
In ancient Greek theatre, all performers were male, and characters, regardless of gender, were played by men, often wearing masks to depict various personas. In the 19th Century melodrama, musical themes, called leitmotifs, and special effects were used to amplify the characteristics of heroes and villains. Melodramas like 'The Phantom of the Opera' illustrate this with clear moral distinctions between good and evil, spectacular theatrical elements, and stock characters.
The iconic use of masks dates back to Greek tragedies, where they were a practical means for actors to assume multiple roles and enhance voice projection. Larger-than-life portrayals were also achieved by wearing platform boots called cothurni. In opera, while not using masks, the vocal range and timbre serve a similar purpose, conveying the symbolic weight of the characters.