MThd MTrk + X Y Q Q Q / MTrk Acoustic Grand Piano /P/ g/PL/ 40PL0 4/P/ g0P0 g2P2 g4P4 g2P2 g0P0 g/P3/ M1PL1 42P2 g2Pf2 4PL4 46P6 g2P2 g>P> g