machine_question: what guitar did the composer of Heart-Shaped Box
question: What guitar was favored by the composer of "Heart-Shaped Box"?
sparql: PREFIX ns: <http://rdf.freebase.com/ns/>
  SELECT DISTINCT ?x
  WHERE {
  FILTER (?x != ?c)
  FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
  ?c ns:music.composer.compositions ns:m.04241j . 
  ?c ns:music.guitarist.guitars_played ?x .
  }
  
webqsp_question: what guitar did kurt cobain