In
music,
themes are frequently called
motifs. After the principal theme or motif is announced, a second voice takes up the second
melody, called a
countertheme or
countermotif. In a three-part
fugue, the principal theme is announced three times in three different voices --
soprano,
alto,
bass -- or some variation of that. In a four-part fugue, the principal motif is announced four times. A
leitmotif is a theme associated with a particular character in a play.