Question: Which instrument created by Bartolomeo Cristofori was played by Scott Joplin?
Answer(s):
answer: Piano

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.07b69)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.07b69 ns:music.group_member.instruments_played ?x .
?x ns:law.invention.inventor ns:m.01c_8n . 
}