/*
 * Return the Music which is currently set on the music channel (i.e.
 * was played most recently) or nil if no Music has ever been played.
 *
 * NOTE: The current Music could be playing, paused, or stopped. Use
 * #playing? or #stopped? if you want to know whether the current
 * music is still playing.
 */
static VALUE rg_music_current( VALUE klass )
{
  return rb_iv_get( cMusic, "@current_music" );
}