What can i do to help you further? What information do you need?

EDIT:

If its scummvm specific things:
Im playing monkey island 1 and 2.
In the game specific settings:
-Audio tab: Overwrite global settings (checked) - Musicdevice = Midi Through [ALSA]
-Midi tab: Overwrite global settings (checked) - GM-Device = NONE - mixed adlib/midi mode (checked)
-MT32 tab: Override global settings (checked) - MT32-device = Midi Through [ALSA]

DOSShark wrote on Today, 18:21:

What can i do to help you further? What information do you need?

How can I reproduce your error simply using Wine + ScummVM on my Linux Mint without all the other stuff you mentioned?
BTW, I do not think that I can do anything anyway since most likely the problem is not with Munt VSTi but with some of the Linux component(s) you use. The hard thing is to identify which one.

Ok.
(1) Use ScummVM.
(2) Monkey Island 1 and 2.
(3) Set game specific settings in the way i mentioned in my last edited post above.
(4) In your player set midi through port as input
(5) Use your munt vsti Instrument with default settings.
(6) Play the game(s).
(7) On Monkey 1 the intro music is already broken for me.

DOSShark wrote on Today, 18:35:

Ok. (1) Use ScummVM. (2) Monkey Island 1 and 2. (3) Set game specific settings in the way i mentioned in my last edited post abo […]
Show full quote

Ok.
(1) Use ScummVM.
(2) Monkey Island 1 and 2.
(3) Set game specific settings in the way i mentioned in my last edited post above.
(4) In your player set midi through port as input
(5) Use your munt vsti Instrument with default settings.
(6) Play the game(s).
(7) On Monkey 1 the intro music is already broken for me.

Some things should be tried by you first:
1. Play the Monkey Ireland MT-32 Midi file with FSMP first and Munt VSTi loaded. Listen if you can experience the same problem.
2. Eliminate ScummVM from the equation. That is play the Monkey Ireland MT-32 Midi file with another Linux Midi Player through the same port you use with ScummVM so that FSMP + Munt VSTi loaded produce the sound.
Listen if you can experience the same problem.

Here are the MT-32 versions:

I dont have a midi file- the music comes directly from the game.
But i tested dosbox and the game doom with your munt plugin and it works perfect - so its a scumm vm thing.
And this is probably out of your hands.

Thanks a lot for taking your time to help me 😀.

EDIT:
Oh - i didnt see you provided 2 midi files.
I only tested Monkey Island 1 midi and like the doom music data from dosbox this works.

DOSShark wrote on Today, 18:55:

I dont have a midi file- the music comes directly from the game. But i tested dosbox and the game doom with your munt plugin and […]
Show full quote

I dont have a midi file- the music comes directly from the game.
But i tested dosbox and the game doom with your munt plugin and it works perfect - so its a scumm vm thing.
And this is probably out of your hands.

Thanks a lot for taking your time to help me 😀.

EDIT:
Oh - i didnt see you provided 2 midi files.
I only tested Monkey Island 1 midi and like the doom music data from dosbox this works.

Have you also tried point 2. that is not using FSMP for playback but using another Linux based Midi player through the same port as used by ScummVM?
You should also attach a rendered part of the badly sounding ScummVM version as wav/mp3 so that I can have a clue about what you actually hear.
And a screenshot of the Munt VSTi plugin when the bad sound happened ( and a description about at what part it happened).