Question: Who in electronic musical instruments famous people is Serj Tankian and whose Hornbostel-Sachs classification is 531.1?
Choices: Omnichord
sampler
keytar
drum machine
didgeridoo
electronic drum
xylophone
Timbales
theremin
goblet drum
SPARQL: SELECT DISTINCT ?e WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "electronic musical instrument" . ?e <famous_people> ?e_1 . ?e_1 <pred:name> "Serj Tankian" .  ?e <Hornbostel-Sachs_classification> ?pv . ?pv <pred:value> "531.1" .  }
Program:
function: Find
inputs: Serj Tankian
function: Relate
dependencies: 0
inputs: famous people
backward
function: FilterConcept
dependencies: 1
inputs: electronic musical instrument
function: FindAll
function: FilterStr
dependencies: 3
inputs: Hornbostel-Sachs classification
531.1
function: FilterConcept
dependencies: 4
inputs: electronic musical instrument
function: And
dependencies: 2
5
function: What
dependencies: 6
Answer: theremin