A

• [+] American opera companies (4 C, 71 P)
• [+] Argentine opera companies (3 P)
• [+] Australian opera companies (11 P)
• [+] Austrian opera companies (3 P)

B

• [+] British opera companies (34 P)
• [+] Bulgarian opera companies (2 P)

C

• [+] Canadian opera companies (11 P)
• [+] Czech Republic opera companies (1 P)

D

• [+] Danish opera companies (1 P)
• [+] Dutch opera companies (1 P)

E

• [+] Estonian opera companies (1 P)

F

• [+] Finnish opera companies (1 P)
• [+] French opera companies (9 P)

G

• [+] German opera companies (1 C, 13 P)
• [+] Greek opera companies (1 P)

I

• [+] Italian opera companies (4 P)

M

• [+] Moldovan opera companies (1 P)

N

• [+] New Zealand opera companies (1 P)
• [+] Norwegian opera companies (1 P)

O

• [+] Opera houses in Belgium (1 C, 2 P)

P

• [+] Polish opera companies (4 P)

R

• [+] Romanian opera companies (4 P)
• [+] Russian opera companies (2 P)

S

• [+] South African opera companies (1 P)
• [+] Swedish opera companies (4 P)
• [+] Swiss opera companies (2 P)

T

• [+] Thai opera companies (1 P)
• [+] Turkish opera companies (1 P)

U

• [+] Ukrainian opera companies (1 P)