Who made or played the 'whistle' in for a few dollars more?

In "For a Few Dollars More," the distinctive whistle is performed by composer Ennio Morricone. The whistle serves as a memorable motif throughout the film, representing the character Colonel Mortimer, played by Lee Van Cleef. Morricone's score, including the whistle, is integral to the film's atmosphere and has become iconic in the Spaghetti Western genre.