No need to clean(), since that functions makes a mess with -. This worked for me:
If(math(IsMissing(F:...\Artists\Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace([Primary Artist].gif,",_),*,_),//,_),:,_),?,_),\,_),<,_),>,_),|,_)) & IsMissing(F:...\Artists\Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace([Primary Artist].png,",_),*,_),//,_),:,_),?,_),\,_),<,_),>,_),|,_),) & IsMissing(F:...\Artists\Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace([Primary Artist].jpg,",_),*,_),//,_),:,_),?,_),\,_),<,_),>,_),|,_))),[Primary Artist]; /(Missing Artist Art:/), /(Has Artist Art/))&datatype=[list]
The [Primary Artist] field is a custom field where I just have picked the first artist in a list of artists. Use [Artist] if you do not have a list of artists in that field.