What instruments are used to create the heroic sounds and themes in music, for instance like the heroic music in Pirates of the Caribbean, Lord of the Rings, etc.?

It’s very much like what you would hear in a typical marching band. It’s mostly, the brass because they project and are the most powerful. The heroic themes are typically played by trumpets, trombones and French horns. The brass section can create the most power, so they are the main players in that kind of music.

Of course, you wouldn’t have the same power without the percussion section really adding a lot of the drive and energy. And then, there’s the whole orchestra for the most power.

Also notice like the marching bands, that the piccolo is also heavily used in this type of music because it is sonically so high that it really cuts through, unlike the larger C flute which does not project well except for in it’s upper register.