cut off filename prefix and store it as a tag

Hi, I've searched the forum for a while and I can't seem to find the answer to my question. I have a bunch of MP3 and CDG files that have a prefix that I'd like to cut out of the filename (figured out how to do this pretty easily) BUT then store it as the album name tag. Can anyone help me with this? Thank you!

To answer you question completely we have to know what you want to cut off, if all the filenames have the same structure, if the prefix is always the same and so on. As we don't know how you solved this part of your problem (cut off), it is not possible to give a a detailed answer how to do the rest.
So you best give examples how the filename is built and what you want to cut off.

To store a part of the filename to a tag can be done with the convert-menue "Filename - Tag" or depending on the structure of the filename with an action of the type "Format Value" or the type "Guess values".

Use the function Convert>Filename-Tag
As you do not tell us what the filename looks like, I can only give an example.
Use the field variables to address the parts of the filename, e.g. %album%, and insert %dummy% for any part that you do not want.
E.g.
Beatles - Rubber Soul - Nowhere Man.mp3
could be converted like this:
%artist% - %album% - %title%
or
%dummy% - %album% - %dummy%

so I have constant characters SC followed by different 4 digit sequence and a "-". Mp3tag makes it easy to cut the prefix off the filename and just drop it but I want to take the prefix SCxxxx (xxxx is a 4 digit number) and store that as the album name tag while dropping the "-" between the prefix and the artist name. So to summarize, remove prefix from song name, store the respective prefix as the album tag for the respective song. Thanks to both posters for your help!

Question about "song name" ...
... is this the already formatted TITLE Tag-field?
... or is this the filename?

If Filename is something like this ...
SC0000 - any artist name - any other text.mp3
... or ...
SC0000-any artist name-any other text.mp3
... or ...
SC0000-any text.mp3

... then you can do something like this ...

Action "Format value" ... or ... Convert "Tag - Tag" Tag-Field: ALBUM Formatstring: $left(%_filename%,6)

DD.20150612.1127.CEST

The filename is like your example SC0000 - artist - song name. And yes I want to remove the SC0000 and store that as the album tag. How would I enter the script you have created below? Go to Actions then? Thank you!

Convert is better to learn because it has a preview with which you can experiment expressions and immediately see the result.
As an action you just fill the entry fields

Action-type: Format Value
Field: Album
Format String: $left(%_filename%,6)

and if you would like to store the contents of the filename for artist and title too, you could use:

Action type: Guess Values
Source format: %_filename%
Guessing pattern: %album% - %artist% - %title%

So if I use convert, how can I chop the prefix of the filename off and store it in one step and which option under Convert do I use? My fear is that I do this wrong and cut the prefix off the filename but don't store it immediately and therefore it would be gone.

Use Convert>Filename-Tag
to retrieve the data from the filename (poster already showed you an example for a mask: %album% - %artist% - %title%)
There is a preview. So you should be able to see if you get all the data.
Then use Convert>Tag-Filename
with a mask that creates a filename of you liking, e.g.
%artist% - %title%

First:
Always test your actions and converts with duplicates of your files. If you are sure about the result, you can go to the originals.

You cannot do this with Convert in one go but one after the other. This is the same in actions but there you can combine several actions in an action-group that will be executed one after the other.
So your first step has always to be to fill the tags and then rename the filename. The convert-menue contains some predefined actions with the possibility to see the effect in the preview as soon as your defined format string has as valid syntax.
With the actions-menue you fly blind and have to look at the result after the action is executed.

Therefore I wrote that the convert-menue is good for training to define format-strings, especially for beginners. These format-strings are basically the same in actions and when you are satisfied with the result in the preview you can use your format-string in an action group, wehre you can define many actions that can be done in one go in a row.

Convert Filename-Tags
Format-String: %album% - %artist% - %title%
will take all information of your filename and fill the tags.
See this as a mask for your filename.
(Action equivalent: Guess Values)

Format String: %album% - %dummy% - %dummy%
will only fill the album tag.

Convert Tag-Tag
Field: _FILENAME
Format-String: $cutleft(%_filename%,6)
will rename the filename cutting off 6 characters from the left.
(Action equivalent: Format Value)

Convert Tag-Filename
Format-String: %album% - %artist% - %title%
will completely write a new filename with the content of your tags.

There are many other variations possible and the same result can often be accomplished with mp3tag in different ways.
Have a look at the help-file, do some experiments (always with duplicates of your files so that you cannot mess up your originals) and study the numerous variations and examples written in the forum for years.

If you want to remove resp. cut some characters at the left edge from a string, then you may apply the function $cutLeft.

Convert "Tag-Tag" ... or ... Action "Format value" Field: _FILENAME Formatstring: $cutLeft(%_filename%,6)

DD.20150616.1003.CEST

It's been a while but thanks for the help with the tags and renaming. I tested and it worked great! I'm just now getting around to renaming the main files (yep, I made a backup of the files first :stuck_out_tongue: ) and remembered I have files with the same names as the MP3 files that have a CDG extension that will also need to be renamed. Can I rename CDG files with this software or would I need to use another utility? If I have to use another utility do you happen to know a decent one? Thanks!

TD

If you include the CDG in the list of read files in
Tools>Options>Tags
and the new name can be deducted from the folder name or a string constant, you can use MP3tag.

That's what I needed. Thanks!