How many {instrumentation} are to/by {harps} ?
What are the kinds of Harps someone can play?
How many instrument are for harps
SELECT ( COUNT ( ?x ) AS ?z ) { ?x property:instrumentation resource:harp }
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/P870> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q47369 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P870 wd:Q47369 }
24