AMAJ

Set to 7 different clues across 12 published puzzles, most often “Key of Beethoven's Symphony No. 7: Abbr.” — The New York Times, Thursday, 24 November 2005.

4 letters

Every clue on record, most used first

Key of Beethoven's Symphony No. 7: Abbr.4 times
The New York Times — Thursday, 24 November 2005
Key with three sharps: Abbr.2 times
The New York Times — Tuesday, 8 September 2009
Key related to F# minor: Abbr.2 times
The New York Times — Monday, 21 May 2007
Setting of Mozart's only clarinet concerto: Abbr.once
The New York Times — Saturday, 27 November 2010
Key of Beethoven's Seventh: Abbr.once
The New York Times — Wednesday, 9 September 2009
Key to Mozart's 21st: Abbr.once
The New York Times — Sunday, 7 April 1996
Key of Mozart's Symph. No. 29once
The New York Times — Tuesday, 21 February 1995