Windows comes complete with a MIDI Synthesiser: the Microsoft GS Wavetable Synth. There are various reasons why you might want an alternative. A popular one, available free of charge (but with the possibility of a voluntary donation if you like it), is the Virtual MIDI Synth from CoolSoft. But some Mozartists have had difficulty installing it. So we appealed for help, and Jeroen Neve stepped up to the mark with an explanation of how to do it. Here is his explanation - which I've only slightly embellished.
Two components are needed.
1. The VirtualMIDISynth from CoolSoft ("dove il Software è Cool") is a Windows-compatible software synthesiser. When installed, it runs as a program in the background, and causes Windows to make available a MIDI-out port which Mozart can use for play-back.
2. The actual sounds are synthesised using a fairly large amount of data (typically >100MB) stored in a 'sound font' file. The VirtualMIDISynth can use a variety of choices of sound font, and many are available free of charge. This explanation gets you started with one of them.
A recommended one is "GeneralUser GS 1.47" which is freely available from: http://www.schristiancollins.com/generaluser.php
1.1 Download this soundfont (file GeneralUser_GS_1.47.zip).
1.2 Unzip it. This will generate a folder GeneralUser_GS_1.47 containing a number of files including the sound font.
1.3 Move this folder somewhere convenient on your computer from where it will be used.
On my own computer, I created a new folder within C:\ProgramData\ as this seemed like a sensible place. So now I have mysound font data in the new folder C:\ProgramData\SoundFonts\GeneralUser_GS_1.47\... and, if or when I download any more sound fonts, they can go there in parallel.
The file you get is CoolSoft_VirtualMIDISynth_1.17.1.exe (or maybe a later, similarly named, version of the program). This is the installer program.
This is a standard "wizard" with assorted choices and Next buttons.
3.1 At one point it launches a Web Browser to show you where you can download some free sound fonts. Ignore this for now, as you already have one!
3.2 Instead, stay with the wizard, until you see a (blank) list of sound fonts, and use the accompanying + button to add the one from where you put it in (1.3) above. The wizard is looking for the .sf2 file in the folder you stored.
3.3 Follow the wizard and Finish.
4.1 Launch Mozart
4.2 Go to the Preferences command and the "MIDI ports" tab of the ensuing dialogue box.
Before I installed CoolSoft VirtualMIDISynth, the list of MIDI-out ports at the bottom right looked like this:
After I installed CoolSoft VirtualMIDISynth, the list of MIDI-out ports at the bottom right looked like this:
4.3 Select the Coolsoft VirtualMIDISynth as shown, and press OK
4.4 Play back your favourite piece in Mozart. The sounds are now being synthesised by the CoolSoft VirtualMIDISynth.