Not per se. It can create new ones. The shortest rest should go and that rest should be substracted from the others as well.
It would help a lot if I could take a look at the exact content of the strings, but I'm not going to dedicate hours to fixing this little thing. 
Gives errors and/or doesn't load on MSX, crashes in Windows cmd (namely the NTVDM.exe part).
It works here in cmd: just write -> mgscwin ---- that should work...
If I try to compile any .MUS from Koicihro's page, they work with that program...
It didn't crash this time. So now I have the new .MGS file, what should I open it with to modify (or at least have a look)?
MuSiCa says it can't find the files, both with the .MGS and the .MUS (seems to only accept .MSD), Nerlaska's Windows application keeps crashing with it, and Notepad gives this:
MGS313 [MSX2] ƒEƒVƒƒƒX -Opening- – * j Uµ ÿ ÿÿÜÜ ÿÿdÈ ÿÿdÈ ÿÿd´ ÿÿdÈ ÿÿÈ ÿ,`W T ZBËDÑ9N2424949N2O9N2424949N2O9N24249ÌD49N2O9N2494O94242O9N2O9Ë‚D494242O94ÌDÑ9N249N249N4249N24249B΃DÓ)H€É9΃D)$+$N0$`@$H€È4΃D"$!$O)`D) + ND 0"0O+0'0)H€É9΃D)$+$N0$`@$H€È4΃D"$!$)`D) + DN 0"0O+0'0)`@)H€È9ÿ,`B€ÉÑ<9N2424949N2O9N2424949N2O9N24249Ê49N2O9N2494O94242O9N2O9Ë‚D494242O94€ÉÑ9N249N249N4249N2424B€ÍÑ)0Ê9Ç9Ï„D$$'$9'0@' €É' Ï„D7'$%$4€Í&0Ê6Ï„D6)$+$N1O%0€É5Ï„D577;W + Y ûÿB Ï…ÑDW )Y ûÿD124W Ï…9€È9Y ÷ÿÏ…948D)W 'Y ûÿD024W Ï…7€È7Y ÷ÿÏ…748D)W &Y ûÿDO9;N6W Ï…6€È6Y ÷ÿÏ…724D&W %Y ûÿD59DN OW 'Y ûÿD7;DN"OD)`@)H€È9ÿ,`W T ZB̆DÐ9N2424949N2O9N2424949N2O9N24249͆D49N2O9N2494O94242O9N2O9̆D494242O94͆DÐ9N249N249N4249N24249W_ BËDÑ9N2424949N2O9N2424949N2O9N2424949N2O9N2494O94242O9N2O9494242O94X Ñ9N249N249N4249N24249Y ŸÿB ÌDÑ9;NF02F4579B΃DÓ$H€È4΃D$$'$9'0€É7΃D7'$%$4Z O)H9)$+$N1W )0Y ûÿW '0Y ûÿ$`@$H€È4ÿ
Who wants to compile a MML file (usually .MUS extension) for MGSDRV, with MGSC ported to Windows, can either use online compiler from BREZZA/Digital-Sound-Antiques/Okaxaki/Mitsutaka Okazaki clicking on MML Editor Tab at MSXplay-js or compile from source his GitHub C++ project or use a compiled Windows 64-bit .exe built by me with Visual Studio 2017.
If someone can screencap the contents of the strings for me, I could probably explain what changes to make.
I guess we are talking about UINTROS.MUS
; [MSX2] ウシャス SCC-Arr. -Opening-
;
; (C) KONAMI 1987
#opll_mode 1
#title "[MSX2] ウシャス SCC-Arr. -Opening-"
#tempo 150
; Env & Macro
; == Melody ==
@r0 = {1,0,255,0,0,0,0,0}
@r1 = {1,0,255,255,220,220,0,0}
@r2 = {1,0,255,255,100,200,0,0}
@r3 = {1,0,255,255,100,200,0,10}
*1 = {v11@1q8}
*2 = {v12@1q8}
*3 = {v11@2q8}
*4 = {v14@3q7}
; == BASS ==
@r4 = {1,0,255,255,100,180,0,20}
@r5 = {1,0,255,255,100,200,0,10}
*5 = {v15@4q8}
*6 = {v15@5}
; == SUB ==
@r6 = {1,0,255,255,25,200,0,10}
*7 = {v12@6q8}
*8 = {v13@6q8}
*9 = {v12@1q8}
; == Intro ==
@s00 = { 001931475A6A757D7F7D756A5A473119 8090A0B0C0D0E0F00010203040506070 } ;Intro
@r10 = {1,0,255,255,200,200,0,10}
*10 = {@00@r10v7q8}
; == Melody ==
@s01 = { 80889098A0B0B0B8C0C8D0D8E0E8F0F8 00081018202830384048505860687078 } ;LongTone
@r14 = {1,0,255,255,100,100,0,7}
*14 = {@01@r14v15q7 h12,0,3,-3 ho \0}
@r15 = {1,0,255,255,255,255,0,7}
*15 = {@01@r15v3q7}
; == BASS ==
@s02 = { 70707070707070708080808080808080 70707080808070707070808080808080 } ;BASS
@r16 = {1,0,255,255,100,110,0,6}
*16 = {@02@r16v7q8}
@r17 = {1,0,255,255,100, 90,0,10}
*17 = {@02@r17v7q7}
; == Drum ==
; --------------------------------- ;BD
@e20 = {1,0,F0,y7,185}
*20 = {@e20 v15 p50 o1b}
; --------------------------------- ;Hat
@e22 = {2,0,FD0,y7,185}
*22 = {@e22 v11 o5g}
@e25 = {2,2,FC:4B:4A:4.9:4.8:4.7:4.6:4.5:4,y7,185}
*25 = {@e25 v12 o5g}
@r27 = {2,10,255,255,255,160,1,10}
*27 = {@r27 v13 o5g}
; --------------------------------- ;Snare 1
@e23 = {1,0,F,/2,n8CBA98765,y7,185}
*23 = {@e23 v15 o1c}
; --------------------------------- ;Snare 2
@e24 = {2,20,F,/1,F,/2,n16,BA,y7,185}
*24 = {@e24 v12 o3a}
; --------------------------------- ;Snare 2
*26 = {@e24 o3a}
; == init ==
12345678 v0c
; == Intro ==
; -- PSG --
1 l32 *1o2a>ded eaea >dde deae a>dd edea *2ea>ddeae ddea >dea>e dea>d edea
2 l32 @0v9o2ra>ded eaea >dde deae a>dd edea v10ea>ddeae ddea >dea>e dea>d ede
3 l32 *7o1a>ded eaea >dde deae a>dd edea *8ea>ddeae ddea >dea>e dea>d edea
; -- SCC --
4 l32 *10 o2a>ded eaea >dde deae a>dd edea ea>ddeae ddea >dea>e dea>d edea
4 [ l32 *10 v3 o2a>ded eaea >dde deae a>dd edea ea>ddeae ddea >dea>e dea>d edea ] l16 *17o1ab>v+cdv+efga
5 l32 *10 [(]5 \-2 r8 o2a>ded eaea >dde deae a \-1 >dd edea )ea \0 >ddeae ddea >dea \-1 >e dea>d edea
5 [ l32 *10 v2 o2a>ded eaea >dde deae a>dd edea ea>ddeae ddea >dea>e dea>d edea ]
; -- mute --
678 l32 v0o2ra>ded eaea >dde deae a>dd edea ea>ddeae ddea >dea>e dea>d ede
; == Melody ==
; -- PSG --
3 [ l32 *1o2a>ded eaea >dde deae a>dd edea ea>ddeae ddea >dea>e dea>d edea ] l16 *9o2ab>v+cdv+efga
3 l8 *4o4e4.@0v8e *4e.g.ag4@0v9g *4gg.f.e hf c+ [a4][g4]e2&e4.@0v8e
; -- SCC --
7 l8 *14 o4
8 l8 *15 o4 r. \-1
78 a4.r a.b.>ce2&e4.r d.c+.c4d4ce2&e4.r d.c+.a2a16b16>c4d4c+ f+[*6f+@0v8f+]*6gdeq7f+8 [f8]q6faq7>c8 <[g8]q6gbq7>d8 c+ f+[f+r] gdeq7f+8 [f8]q5faq7>c8 <[g8]q5gbq7>d8
Thanks for the effort, Giangiacomo Zaffini 2. This is obviously a more advanced syntax compared to standard MSX MML, but luckily it's still understandable. It's clear to me now.
There is no deliberate delay in this music data, except for ofcourse the 'reverb' channels.
Based upon the gameplay footage on YouTube as well, we can conclude that the (slight) delay is in the music driver itself, not in the strings containing the music data. All the songs seem to start just a bit later than in the original, but it's particularly at the title screen where this can be noticed, as one expects the music to start immediately upon action button press.
The replayer probably needs a little bit of time to 'unpack' or 'decrunch' the data before playback.
I'm pretty sure about this, but if you want to test this theory in practice, try replacing the introduction music with any other song and see if there's a slight delay after pushing the action button as well.
In that case a start and pause before space can be pressed "could" fix it because then unpacking has already been done.
There is no deliberate delay in this music data, except for ofcourse the 'reverb' channels.
Based upon the gameplay footage on YouTube as well, we can conclude that the (slight) delay is in the music driver itself, not in the strings containing the music data. All the songs seem to start just a bit later than in the original, but it's particularly at the title screen where this can be noticed, as one expects the music to start immediately upon action button press.
You're totally right John...
You can put a Breakpoint in adresss 056E3h. That's the "START SONG" routine in game. In "a" you put the song:
;00h: [Stop music]
;80h: Stage 1
;81h: Stage 2
;82h: Stage 3
;83h: Stage 4
;84h: Stage 5
;85h: Stage 2??
;86h: Temple
;87h: Boss
;88h: Boss??
;89h: Select Stage
;8Ah: Intro - Start
;8Bh: Interlude
;8Ch: Ending
;8Dh: Dead
;8Eh: Game Over
But the interrupts are disabled in all process at "start playing" routine... so at the beginning of the "PLAY routine" in the interrupt must be still some START process...
Thanks for the help to everyone!! of course!!
