Question: Who coached the sports franchise that had the fight song "Steelers Polka" during the year 2005?
Answer(s):
answer: Bill Cowher

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:sports.sports_team.fight_song ns:m.0j_8yp9 . 
?c ns:american_football.football_team.historical_coaching_staff ?y .
?y ns:american_football.football_historical_coach_position.coach ?x .
FILTER(NOT EXISTS {?y ns:american_football.football_historical_coach_position.from ?sk0} || 
EXISTS {?y ns:american_football.football_historical_coach_position.from ?sk1 . 
FILTER(xsd:datetime(?sk1) <= "2005-12-31"^^xsd:dateTime) })
FILTER(NOT EXISTS {?y ns:american_football.football_historical_coach_position.to ?sk2} || 
EXISTS {?y ns:american_football.football_historical_coach_position.to ?sk3 . 
FILTER(xsd:datetime(?sk3) >= "2005-01-01"^^xsd:dateTime) })
}