Question: What kind of guitar does the person who wrote "Little Martha" play?
Answer(s):
answer: Gibson Les Paul

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.lyricist.lyrics_written ns:m.04wfy_ . 
?c ns:music.guitarist.guitars_played ?x .
}