This particular dissonant synth sound?

[Yoozer]

"Underlying" is kind of meaningless - are you talking about chord, lead, bass?

At 1:33 I hear it clearly if it's what you're talking about - it's not dissonant, though, it's a perfectly valid 7th chord.

[aardwolves]

Sorry, I don't have much knowledge on theory so, I couldn't hear it was a 7th.

Yeah, I guess it's the lead on the track but, it's actually audible from the very beginning of the track.

I just want to know how you can achieve that kind of synth sound. To me, it sounded like the oscillators were pitched differently but, I'm not good at synthesis.

[Yoozer]

It's more likely that someone lowpassed the hell out of it and then turned up the cutoff very slowly.

[Disco Cubist]

Edit! Listen to the track before posting a reply next time!

Detuned sines or filtered saws are it...gently Lfo mod the fine pitch of one Osc and you're there.