Polonaise in C major Op.49
Лядов для духового оркестра
(Lyadov is also spelled Liadov or Liadow - no confusion in Russian: Лядов)
Polonaise In Memory Of Pushkin - Полонез памяти А.С.Пушкина
This polonaise was written for the celebrations of the centenary in 1899 of the birth of Pushkin. Every band in Russia has a version of it in B flat, but there is no real need to transpose it especially as the E flat bridge section then becomes quite muddy, and C major is the key of rejoicing.
For more about Anatoly Lyadov and ceremonial polonaises, see the Polonaise in D major, Op.55.