Question: How many artists have collaborated with famous guitar players?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:notableInstruments <http://dbpedia.org/resource/Guitar> . ?x onto:associatedMusicalArtist ?uri  . ?uri rdf:type onto:Artist}