At the risk of sounding like I am reviewing the music or some movies:

Morricone’s music was used to great effect to keep audiences entertained during Sergio Leone’s long sequences in which little happened on screen. Leone did this in order to enhance suspense or to create other effects (e.g. in the movie “The Good, The Bad, And the Ugly,” he gave us a sense of sadness over the waste of life during the American Civil War). If it weren’t for the brilliance of Morricone, the images would not have had the same meaning, and the sequences would have had to be shortened, because the audience would want the film to move along, as in the other movies of the time. The combination of imagery and music heightened the audience experience, and that is why we so appreciate Leone’s brilliant movies. (In a way, I think that finding Morricone was the most brilliant move of Leone’s career.)

Earlier, Hitchcock was able to do a similar 5-minute sequence in “north By Northwest” when Cary Grant’s character is waiting at a bus stop, but such imaginative filmmaking is rare. Together, Leone and Morricone were exceptional.

All this is to say that it was the imagery that accompanied the music and the music that accompanied the imagery that were important. I think that the Spaghetti Western Orchestra understood this relationship and created new imagery to make the music come to life for us. The emotions that they elicit are different, but these enhanced emotions may be why some/many/most of us prefer their performance.

On the other hand, the BBC Concert Orchestra, being a regular orchestra, heard only the music (still brilliant, but missing that special something).

sort of like drag racing in a Rolls Royce?