The Imperial March Played in a Major Key Sounds Happy and Upbeat
by Justin Page from Laughing Squid on (#1508K)

In November 2015, Ian Gordon of Muted Vocal played John Williams' iconic "The Imperial March" theme song from Star Wars in a major key and gave it a happy, upbeat sound. He also gave the main Star Wars theme song an injection of happiness by playing it in a minor key.
Bit of background relating to the creation of these things:
Though I have been a musician for many years, I have no real knowledge of music theory. I learn the themes by ear and then record them into Cubase. From there I basically mess with the notes until they sound 'happier' or 'sadder' depending on the theme. That's all there is to it.
via reddit