Hurrah! What a wonderful performance! Dear performers! I congratulate and wish you all the best to perform well in more and more pieces like this. When all the four of you simultaneously play it gives the effect of playing duplication of same copy of melody on both upper and lower octave with addition of two more notes on foot-pumped harmonium or melody on right hand piano style keyboard with bassline and chord progression on left hand button type manual simultaneously on accordion. When one of you play and other three of you keep silence at some parts the voice of every individual instrument is clearly understandable.
