Table: yeomen_guard_roles
Columns: role
d_oyly_carte_1920_tour
d_oyly_carte_1930_tour
d_oyly_carte_1939_tour
d_oyly_carte_1945_tour
d_oyly_carte_1950_tour

Question: D'Oyly Carte 1920 Tour of hugh enes blackmore is what D'Oyly Carte 1930 Tour?
SQL: SELECT "d_oyly_carte_1930_tour" FROM yeomen_guard_roles WHERE "d_oyly_carte_1920_tour" = 'hugh enes blackmore'

Question: D'Oyly Carte 1939 Tour of richard walker involves what D'Oyly Carte 1945 Tour?
SQL: SELECT "d_oyly_carte_1945_tour" FROM yeomen_guard_roles WHERE "d_oyly_carte_1939_tour" = 'richard walker'

Question: D'Oyly Carte 1920 Tour of james turnbull is what D'Oyly Carte 1945 Tour?
SQL: SELECT "d_oyly_carte_1945_tour" FROM yeomen_guard_roles WHERE "d_oyly_carte_1920_tour" = 'james turnbull'

Question: Role of wilfred is what D'Oyly Carte 1945 Tour?
SQL: SELECT "d_oyly_carte_1945_tour" FROM yeomen_guard_roles WHERE "role" = 'wilfred'

Question: D'Oyly Carte 1939 Tour of sydney granville had what D'Oyly Carte 1950 Tour
SQL: SELECT "d_oyly_carte_1950_tour" FROM yeomen_guard_roles WHERE "d_oyly_carte_1939_tour" = 'sydney granville'

Question: D'Oyly Carte 1930 Tour of john dean involved what D'Oyly Carte 1945 Tour?
SQL: SELECT "d_oyly_carte_1945_tour" FROM yeomen_guard_roles WHERE "d_oyly_carte_1930_tour" = 'john dean'