How do you add a custom name to "Comment" section as the defalut?

[ohrenkino]

You would have to execute this action each time you want to set the value - it will not work automatically.

Create an action of the type "Format value" for COMMENT
Format string: MUSIC from Joe

here is the HowTo that describes how to create an action:

Actions and batch-operations

How to create a new action? First, create a new action group via Actions > [Actions] Actions or Alt + 6. Then, click on the button [New] New and give your action group an expressive name, e.g., "All tag fields Upper Case". This action group can be applied to the selected files after you have added one or more actions to it. Now, you can create a new action in your action group via the button [New] New and choose the desired action type from the list. At the moment the following action types …