Table: sweeney_todd_tony_awards
Columns: year
award_ceremony
category
nominee
result

Question: Which Year has a Nominee of stephen sondheim, and a Category of the best original score?
SQL: SELECT "year" FROM sweeney_todd_tony_awards WHERE "nominee" = 'stephen sondheim' AND "category" = 'best original score'

Question: Which Result has a Category of the best costume design?
SQL: SELECT "result" FROM sweeney_todd_tony_awards WHERE "category" = 'best costume design'

Question: Which Nominee has an Award Ceremony of tony award, and a Category of the best performance by a leading actor in a musical?
SQL: SELECT "nominee" FROM sweeney_todd_tony_awards WHERE "award_ceremony" = 'tony award' AND "category" = 'best performance by a leading actor in a musical'