Let us play the piano

“Canon” (in brackets means that to press at the same time)

H-JLO E-ILN F-HJM C-GIL
D-FHK A-EHJ D-FHK E-GIL
(HQ)-JLO (EP)-GIL (OF)-HJM (NC)-GJL
(MD)-FHK (LA)-CEH (MD)-FHK (NE)-GIL
ONOH (G B )LIJ (CH)ONM (CN)QST
(DR)QPR (QA)PON (DM)LKJ (EI)KJI
(EH)IJK (EG)ILK (FJ)MLK (CL)KJI
(DH)FMN (AO)NML (DK)JIM LML
(SJ)QRS-QR(SE)LMNOPQR
(FQ)OPQ-JK(GL)MLKLJKL
(FK)MLK-JI(JE)IHIJKLM
(FK)MLM-NO(GL)MNOPQRS
(SI)QRS-QR(SE)LMNOPQR
(FQ)OPQ-JK(GL)MLKLJKL
(FK)MLK-JI(EJ)IHIJKLM
(FK)MLM-NO(GL)MNOPQRS
(HQ)-JLO