TASK DEFINITION: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.
PROBLEM: Category: NAMES YOU SHOULD KNOW 
Clue: Sharing her first name with Robin Hood's sweetie, this African-Amer. contralto earned the 1963 Pres. Medal of Freedom

SOLUTION: marian anderson

PROBLEM: Category: HOW DO THEY WORK? 
Clue: Many car salesman work on "straight" this, though you're better off buying from one who's on salary

SOLUTION: commission

PROBLEM: Category: CASH 
Clue: Johnny wowed the MTV crowd with his stark cover of "Hurt", originally by this Trent Reznor band

SOLUTION:
nine inch nails