Hurrah! What a wonderful performance. Dear performers! I wish you all the best to perform well in more and more pieces like this. When all the four instrumentalists simultaneously play in harmony it gives the effect of duplication of same copy of melody on both upper and lower octave (both of the hands) with addition of two more notes (keys) in between to make the entire melody sound as chords on foot-pumped harmonium. Such effect gives pleasant and energetic sense.