Hey, thanks for the feedback.
Well, some things about this kind music is that it's supposed to be fairly cheesy in my opinion. Most of the classic sci-fi themes are. Also, that semitone is because in that chromatic mediant modulation, and where the melody is in that moment in time, the nearest chord tone is a half step away. Emaj to Cmaj has a difference of two half steps between the third and the fifth of Emaj, so that step down I'd argue is the defining feature of the sound. I could have done something else, but to me that voice-leading/flow just feels right.
Hey, thanks a lot! It is not live — it's all virtual instruments.