Question: What musical artist produced the album "Pulse" and sung for Pink Floyd?
Answer(s):
answer: David Gilmour

SPARQL query:
#MANUAL SPARQL
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
  {
    ns:m.01wv9xn ns:music.musical_group.member ?y .
    ?y ns:music.group_membership.member ?x ;
       ns:music.group_membership.role ns:m.0290ngj . #vocals
  }
  UNION
  {
    ns:m.01wv9xn ns:music.musical_group.member ?y .
    ?y ns:music.group_membership.member ?x ;
       ns:music.group_membership.role ns:m.0_sv_90 . #lead vocals
  }?x ns:film.producer.film ns:m.0bhh71 . 
}