query: SELECT ?band ?bandLabel (AVG(?age) AS ?avgAge) WHERE {
    ?band wdt:P31/wdt:P279* wd:Q215380 .
    ?band (p:P740/ps:P740/p:P17/ps:P17)|(p:P495/ps:P495) wd:Q145 . # country of inception / country of origin; Q145 is UK
    ?band p:P527 ?ms .
    ?ms ps:P527 ?member .
    FILTER NOT EXISTS { ?ms pq:P582 [] } .
    ?member p:P569/ps:P569 ?dob .
    BIND (YEAR(NOW()) - YEAR(?dob) AS ?age)
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  } 
  GROUP BY ?band ?bandLabel
  HAVING (AVG(?age) >= 70 && COUNT(?age) > 1)
  ORDER BY DESC(?avgAge)