code: public void append(Music music) {
  		//if appending a music from a part
  		//add a PartLabel to all voices
  		if (!music.m_partLabel.equals(" ")) {
              for (Object m_voice : m_voices) {
                  ((Voice) m_voice).addElement(new PartLabel(music.m_partLabel));
              }
  		}
          for (Object o : music.getVoices()) {
              Voice v = (Voice) o;
              if (!voiceExists(v.getVoiceName())) {
                  //create new voice (in getVoice)
                  //and copy v informations
                  Voice vCopy = getVoice(v.getVoiceName());
                  vCopy.setTablature(v.getTablature());
                  vCopy.setVolume(v.getVolume());
                  vCopy.setInstrument(v.getInstrument());
                  //? vCopy.setFirstBarNumber(v.getFirstBar().getBarNumber());
              }
              getVoice(v.getVoiceName()).addAll(v);
          }
  	}
docs: Concatene the given music object to current one