Double Artist Removal

Not that great at mp3 tag. I have a lot of files that are formated as such %artist%/%artist% and would like them to be only %artist%

E.g.
Chicago/Chicago
changed to
Chicago

How would i do this? Thanks

Have a look at the actions.
Ther is one that removes duplicate fields.

the "remove duplicate fields" removes multivalue tags. they have to be seperated by \\ and it doesn't matter if they actually have the same value.

for
Chicago/Chicago
to
Chicago
i would use:

Action: Format Value
Field: %artist%
Formatstring: $regexp(%artist%,(.+)/.+,$1)

that removes everything from the frist "/" to the end.

or, maybe easier because without regular expressions:

Action: Guess Values
Sourceformat: %artist%
Guessing pattern: %artist%/%dummy%

Tried both of your strings and they do infact remove everything after / but some artist are written like this t-pain/jay-z/50 cent and i want to keep those ones. How do i make it for exactly the same before and after /?

or even better (and more complicated)

Action: Format Value
Field: ARTIST
Formatstring: $if($eql($regexp(%artist%,^(.+)/(.+)$,$1),$regexp(%artist%,^(.+)/(.+)$,$2)),$regexp(%artist%,^(.+)/(.+)$,$1),%artist%)

That only removes what comes after "/" if it is exactly the same as befor the "/"

So:
Chicago/Chicago to Chicago
but
AC/DC stays AC/DC

by this, you can use this for a mass renaming without checking every file for it's content.

@pone: you are right of course in repect to mp3tag that you would need a double backslash.
In WMP, though, the slash is interpreted as separator and you will get a group AC and one called DC.
So my advice would be to eliminate all slashs completely and replace them with similar looking character but one with a completely different one like ⁄ (U+2044).
Does not help a lot with the basic problem but should dampen any enthusiasm.

Apply the filter expression:

ARTIST MATCHES "(.+?)/\1"

This should display only those files having ARTIST content like 'Chicago/Chicago'.

To change an ARTIST content like 'Chicago/Chicago' to 'Chicago' apply an action:
Action: Format value
Field: ARTIST
Formatstring: $regexp(%ARTIST%,'(.+?)/\1','$1')

DD.20111018.1414.CEST

thanks Detlev, a good one to know. i alread stumbled about the \1 somewhere, but I thought it's the same as $1 . now i see the difference.