[start sweetly, more acoustic]
You could try double harmonic minor for the melody — D-E-F-G#-A-Bb-C# — it adds a spookiness and sneakiness.

[with more drive]
Incorporate the B Harmonic minor scale.
Same as the regular minor scale except the 7th isn't flatted, very spooky sound

[with gusto!!]
A7 on the last chord instead of A major
[breath]
[offbeat]
Play it on a harpsichord

[getting more unhinged]
The sustained chords at toward the end of each phrase needs the same oompa oompa chug as the middle of that makes sense at all? el oh el

[drum fill]
[build up]
[louder vocals, with impact!]
[half spoken, drop out the beat for impact]
Hey! Try cutting two eye holes into a sheet and putting it over your head while playing the riff. [gang vocals] Hope! this! helps!

[with fervor]
Just scream BOO really loud at the end
[sweetly]
Be dead while playing it?

[spoken through old timey microphone, static noise]
LADIES AND GENTLEMAN GATHER ROUND
GATHER ROUND

[passionate]
BOO!!!

[laughing]