Delete 1st part of file name

[Dirk]

I want to del the artist in front of the song.
Example 01 - Medicine head_One & One Is One.mp3
02 - Melani_What Have They Done To My Song.mp3
03 - Men Without Hats_Safety Dance
I had a formula to do it, but that was long ago, can't remember. What I do remember is that I had to change the - character to _ character.
Tnx

[Luuk]

It depends if you want to delete the 1st-part of filename, or only the artist.