Unfortunately that extremely beautiful flute theme does not appear in the film. The music in the SW is by Angelo Francesco Lavagnino and his genius is emphasized by his likewise fantastic theme for Requiem For A Gringo.
I wonder why the flute theme on the Wild East DVD appears (as far as I observed) only on the menu for Extras and on the Picture Gallery but not in the movie. Neither does it appear on the English nor the Italian Trailer. I guess the flute theme is also by Angelo Francesco Lavagnino, but am not 100 % sure. Maybe from another movie ?
Kill The Wicked ! has several nice musical themes but with that flute theme included I would have rated it a 8/10 SW 
From the movie : https://youtu.be/vHxql_k1pRs?t=56
And the by me recently bought A Gun For 100 Graves/Pistol for a Hundred Coffins also has a very nice music theme by Angelo Francesco Lavagnino. I liked the main theme there as well very much, but didn’t check out who was the composer.
