Question: Who worked as a singer and payed Lt. Uhura?
Answer(s):
answer: Nichelle Nichols

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.012gkt)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.012gkt ns:film.film_character.portrayed_in_films ?y .
?y ns:film.performance.actor ?x .
?x ns:people.person.profession ns:m.09l65 . 
}