query: #Neujahrskonzert with conductor by country and age
  SELECT ?item ?itemLabel ?conductorLabel ?countryLabel ?age
  WHERE
  {
  	?item wdt:P31 wd:Q339152 ; wdt:P585 ?date ; wdt:P3300 ?conductor .
  	?conductor wdt:P569 ?DOB ; wdt:P27 ?country .
  	BIND(YEAR(?date) - YEAR(?DOB) as ?age) .
  	SERVICE wikibase:label { bd:serviceParam wikibase:language "fr" }
  } order by ?date