why is it no opra song in heroes2

For some reason the GOG version uses the music from the original HoMM2 release rather than the operatic tracks that were used in the expansion. Due to the way GOG configured their release of HoMM2 it's possible to swap out the original tracks for the expansion tracks by overwriting some of the included ogg files. A more in depth discussion of this can be found here.

I had opera music when I purchased H2 in early 2012. What did they do? Take out the opera music recently.