What is the {opera} for {librettist} of {Philip Glass}
Librettist Philip Glass was in what opera?
At what opera did librettist Philip Glass play in?
SELECT DISTINCT ?k WHERE { ?k property:librettist resource:Philip_Glass . ?k rdf:type ontology:opera }
select distinct ?subj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?subj . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P87> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q189729> . ?subj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q1344> } 
 select distinct ?sbj where { ?sbj wdt:P87 wd:Q189729 . ?sbj wdt:P31 wd:Q1344 } 
Akhnaten Einstein on the Beach Satyagraha La Belle et la Bête The Perfect American