Question: What is the official website of the rock band that is famous for drone music?
Choices:
http://www.pattilabelle.com
http://www.cityofbradenton.com
https://www.uni-leipzig.de/
http://www.vangelisworld.com/
http://www.magd.ox.ac.uk/
http://www.velvetundergroundmusic.com/
http://www.chrysalis-records.co.uk/
http://www.cafonline.com
http://www.kdlang.com
http://www.countyofbristol.net
Answer: http://www.velvetundergroundmusic.com/
SPARQL: SELECT DISTINCT ?pv WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "rock band" . ?e_1 <famous_people> ?e . ?e_1 <pred:name> "drone music" .  ?e <official_website> ?pv .  }
Program:
function: Find
inputs: drone music
function: Relate
dependencies: 0
inputs: famous people
forward
function: FilterConcept
dependencies: 1
inputs: rock band
function: QueryAttr
dependencies: 2
inputs: official website