Soap on a rope, perhaps (5)
I believe the answer is:
opera
'soap' is the definition.
(thesaurus)
'on a rope perhaps' is the wordplay.
'on' says to put letters next to each other.
'perhaps' indicates anagramming the letters.
'rope' is an anagram of 'oper'.
'a' put after 'oper' is 'OPERA'.
(Other definitions for opera that I've seen before include "La Boheme or Rigoletto" , "Music and drama production" , "Norma is one" , "E.g. Macbeth, Falstaff" , "Musical in which all the words are sung" .)