​DOUBLE SHARP raises a note by two semitones, and is denoted by a x, probably an abbreviation of ♯♯. It is singular that the sign should be a less complicated one than that for the single sharp. On instruments of fixed intonation C x = D♮, E x = F♯, etc. The French call it double dièse, and the Germans doppel kreuz. The Germans call the notes eisis, fisis, gisis, etc.