query: #number of songs named after a month per language
  SELECT ?item ?itemLabel ?languageLabel ?monthLabel WHERE {
    ?month wdt:P31 wd:Q47018901.
    ?item wdt:P31/wdt:P279* wd:Q7366; wdt:P138 ?month.
    OPTIONAL{?item wdt:P407 ?language}
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }
  ORDER BY ?languageLabel