How many {instrument} are to/by {vibraphone} ?
In regards to a vibraphone, what type of instrument is it?
What kind of instrument is a vibraphone?
SELECT ( COUNT ( ?i ) AS ?o ) { ?i property:instrument resource:vibraphone }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1303> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q206987 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1303 wd:Q206987 }
199