MUSIC CLASS
'The letter "F", seen <a href="http://www.j-archive.com/media/2008-05-13_DJ_25.jpg" target="_blank">here</a> stands for forte, meaning "to play loudly", but double "F" stands for <a href="http://www.j-archive.com/media/2008-05-13_DJ_25a.jpg" target="_blank">this</a>, meaning "very loudly"'
fortissimo