Question: Jerry Bock's musicals has been adapted from how many things?
SPARQL query:
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:music <http://dbpedia.org/resource/Jerry_Bock> . ?x onto:basedOn ?uri  . }