Question: Which brand of guitar does the music producer which produced Vai Piano Reductions, Volume 1, play?
Answer(s):
answer: Ibanez

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:music.producer.releases_produced ns:m.033jp46 . 
?c ns:music.guitarist.guitars_played ?x .
?x ns:common.topic.notable_types ns:m.05czz29 .
}