Hi there,
I searched at last a long time. I just want to ask if you have any idea where I can find this Song/Opera. The reason is: In an episode of the Simpsons (Episode 19: "Simpsons Tide" from Season 09) a part of this song seems to be played in the background (when the russian man of the U.N. declares that the soviet union still is alive).
I googled a bit and found this: Князь Игорь
The composer seems to be: Алекса́ндр Порфи́рьевич Бороди́н
Or in non cyrillic: Alexander P. Borodin - Prince Igor
Well the part I'm searching for is a choral.
Here is a link at youtube
http://www.youtube.com/watch?v=Rt8sEB0NVcY
Maybe you know this episode and maybe you know where I can find the opera.

Many thanks for your help.
Greets from Germany
Octavianus
PS: This site is great!