Hello there, my head is spinning after spending hours trying to make this work.
I filter to locate tracks I want to edit:
"$meta_sep(Artist,\\)" HAS \\
If album artist name UB40 differs from the artist name (for example UB40\Chrissie Hynde), add "(feat. Chrissie Hynde) to the title and filename. If this is done, subsequently remove Chrissie Hynde from the artist list.
Additionally, I want to add further conditional rules (I know I have mentioned these somewhere else but I am completely lost) for one or more ADDITIONAL ARTISTS. TITLE (feat. ADDITIONAL ARTIST 1, ADDITIONAL ARTIST 2 & ADDITIONAL ARTIST 3). For less than three, it would be TITLE (feat. ADDITIONAL ARTIST 1 & ADDITIONAL ARTIST 2). FILENAME would be the same except including TRACK at the start with padding (01) for example.
[#1]
T=5
F=FEAT_ARTIST
1=$if($neql(%artist%,%albumartist%),' (feat. %feat_artist%)','')
[#2]
T=5
F=TITLE
1=$if($neql(%artist%,%albumartist%),%title%[ (%feat_artist%)],%title%)
[#3]
T=5
F=TRACK
1=$num(%track%,2)
[#4]
T=5
F=ARTIST
1=%albumartist%
[#5]
T=5
F=ARTISTS
1=%albumartist%
This might be along the right lines:
Guess value
$if($eql(%artist%,%albumartist%),%feat_artist%,%artist%)