Editing

Tagging can be done using the tag panel.

Multiline editing

A fast way is in place editing using  the multiline facility.

In the column you which to modify:

Copy/Move fields

One of the library tools to easily move or copy data from one tag to another.

Excel style expressions

You can use expressions while editing starting with an equal just like Excel .

To change:
I. Allegro
II. Adagio
III. Allegro

to:


Concerto for trumpet in E Op.17 - I. Allegro
Concerto for trumpet in E Op.17 - II. Adagio
Concerto for trumpet in E Op.17 - III. Allegro

Multiselect all the files and edit the name (F2 for in-place, or use the Tag Action Window) and type:
=Concerto for trumpet in E Op.17 - [Name]

You can undo (Ctrl+Z) if it doesn't work like you wanted.

Source

You can use more advanced expressions to populate a field.