In addition to the snippets posted by drakinite you could also have a look at the swapArtistTitle addon which comes with mediamonkey.

// Get selected tracklist
let list = uitools.getSelectedTracklist();
// For each track, change the title and save each track individually.
list.forEach(track => {
  track.title = track.title + 'hello world';
  track.commitAsync();
});

// Get selected tracklist
let list = uitools.getSelectedTracklist();
// For each track, change the title
list.forEach(track => {
  track.title = track.title + 'hello world';
});
// Then, save the entire list. (commitAsync() is also a method of the Tracklist class)
list.commitAsync();

Hello,

Good question! I'd recommend starting by reading this introduction to MM5 addons here: https://www.mediamonkey.com/wiki/Getting_Started_(Addons)

The method that you are looking for is the commitAsync() method of the Track class: https://www.mediamonkey.com/docs/api/classes/Track.html

There are multiple ways to get a Track object; one of which is the uitools.getSelectedTracklist, which returns a Tracklist object: https://www.mediamonkey.com/docs/api/classes/Tracklist.html

For a simple example, if you wish to add some text to the title of every selected title, here are two ways you can do it:

[code]
// Get selected tracklist
let list = uitools.getSelectedTracklist();
// For each track, change the title and save each track individually.
list.forEach(track => {
track.title = track.title + 'hello world';
track.commitAsync();
});
[/code]
Or:

[code]
// Get selected tracklist
let list = uitools.getSelectedTracklist();
// For each track, change the title
list.forEach(track => {
track.title = track.title + 'hello world';
});
// Then, save the entire list. (commitAsync() is also a method of the Tracklist class)
list.commitAsync();
[/code]

Hello,

I'm looking for a VBS-Script or an Information how to create a new script to change TAG's in an MP3-File. I wrote a Script to change TAG's in the MM-Database, but it doesn't work whithin the File.

Thanks and Greeting from Austria