query: SELECT ?composition (SAMPLE(?composerLabel) AS ?composer) (SAMPLE(?title) AS ?title) (GROUP_CONCAT(?otherInstrumentLabel; SEPARATOR = ", ") AS ?otherInstruments)
  WHERE
  {
    ?composition wdt:P870/wdt:P279* wd:Q1444;
                 wdt:P870 ?otherInstrument.
    FILTER(?otherInstrument != wd:Q1444).
    OPTIONAL {
     	?composition rdfs:label ?title.
      FILTER(LANG(?title) = "en").
    }
    OPTIONAL {
      ?otherInstrument rdfs:label ?otherInstrumentLabel.
      FILTER(LANG(?otherInstrumentLabel) = "en").
    }
    OPTIONAL {
      ?composition wdt:P86 ?composer.
      ?composer rdfs:label ?composerLabel.
      FILTER(LANG(?composerLabel) = "en").
    }
  }
  GROUP BY ?composition