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.

Category: CLASSIC COUNTRY 
Clue: 1 of 3 original members of the Country Music Hall of Fame
hank williams, sr., jimmie rodgers & fred rose

Category: THE ELEMENTS 
Clue: Most fluorescent lights are filled with a combination of argon & this element, Kr
krypton

Category: CLASSICAL MUSIC 
Clue: His Symphony in B Minor wasn't his only unfinished composition -- just the most famous

franz schubert