query: SELECT DISTINCT ?item ?itemLabel WHERE {
    ?item wdt:P826 wd:Q277793; # tonality: A major
          ?wdt [ wdt:P463? wd:Q18233 ]. # linked via any property (since I don’t know if it should be “composer”, “performer” or something else) to ABBA or one of its members
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }