How many movies music composers are associated with Demis Roussos ?
SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/property/associatedActs> <http://dbpedia.org/resource/Demis_Roussos> . ?uri <http://dbpedia.org/ontology/musicComposer> ?x  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Film>}
Demis_Roussos