The Weeknd "Open Hearts" Serum Tutorial & Breakdown

The Weeknd's album Hurry Up Tomorrow, released on January 31, 2025, is the final chapter in a trilogy that started with After Hours (2020) and continued with Dawn FM (2022). The album explores redemption, time and self-reflection, showing his artistic and personal growth.

One of its standout tracks, "Open Hearts", blends synth-pop and R&B, creating a rich, atmospheric sound. Co-produced by The Weeknd, Max Martin and Oscar Holter, the song was first introduced as an immersive experience in collaboration with Apple Vision Pro.

In this tutorial, we'll break down the sound design of "Open Hearts" and walk you through recreating each element in Xfer Serum: the bass, the slap bass, the pad, the arp, the two-layer synth and the piano stabs.

By the end, you'll have the skills to recreate "Open Hearts" in Serum and apply these techniques to your own productions.

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The Bass

This track opens with a rich, distorted bass that instantly sets the mood. To recreate it, start with oscillator "A" using the Basic Mg wavetable and pitch it down an octave. For oscillator "B", select the ICanHasKick wavetable and lower it by an octave as well. In the sub oscillator, choose a Saw wave and drop it two octaves.

Next, set LFO 1 to a quarter-note rate and assign it to modulate the amp level in the Matrix tab. Now for the key touch: go to the FX tab, add an EQ, and boost everything above 2 kHz by around 7 dB using a high shelf.

The Slap Bass

Every now and then, a punchy slap bass cuts through, adding groove and energy to the track. To recreate it, we use Serum as a sampler. First, we recorded a C note on our Fender Jaguar Bass and loaded it into Serum's noise oscillator. Turning on one-shot mode and pitch tracking keeps the sample in tune with any MIDI note we play.

To add warmth and depth, we layer in a Sweep20 wavetable on oscillator "A" and a Sine wave on oscillator "B". These extra layers thicken the sound, making the bass fuller and more dynamic.

The Pad

At the beginning of the track, these pads play alongside the bass. To create them, we used a PWM_Mdc waveform in oscillator "A" and a SawRounded waveform in oscillator "B". The sound starts with a low-pass filter cutting everything above 1 kHz. As the song moves from the verse to the chorus, the filter gradually opens up to around 3 kHz, which is done with automation. LFO 1 is also set up as a quarter-note sidechain on the amp for a rhythmic pulsing effect.

The Arp

As we enter the bridge of the song, this arpeggiated sound comes in. To recreate it, we use a Jno wavetable in oscillator "A" and a PWM MG wavetable in oscillator "B". The key to shaping the tone is envelope 1, which modulates the filter cutoff, while the filter resonance is set to around 40%.

For the most important part of the sound design, head to the FX tab and add a half-note ping-pong delay along with a generous amount of reverb to create depth and movement.

The Synth

Recreating this synth sound was a challenge. To get the tone right, we had to get creative with layering, blending multiple elements to capture the depth and richness of the original.

Layer 1: Warmth and Body

For the first layer, we focused on capturing warmth and body. We started with a SQR_SAW_Wrd in oscillator "A", set to 9 voices for a wider, fuller tone, and a Basic Mini in oscillator "B", also with 9 voices, for added depth. To get that brassy character, we used envelope 2 to modulate the filter cutoff, with the attack set to 80 ms for a smooth opening.

Layer 2: Air and Brightness

For the second layer, we wanted to add air and brightness to the patch. We used a Basic Mg in oscillator "A" and an ICanHasKick in oscillator "B", both set to 3 voices for a wide yet controlled texture. The filter cutoff is modulated by envelope 1, with the attack set to 80 ms, just like in the first layer.

For the final touch, use an LFO to modulate the fine-tuning of both oscillators, adding subtle pitch drift for a more organic, vintage feel.

The Piano Stabs

This section comes right after the chorus and is the track's climax, and these piano stabs sound incredible. To recreate them, start with an FMFM wavetable in oscillator "A" and a Harmonic Subtle wavetable in oscillator "B", with its wavetable position knob turned all the way to the right. To add warmth and body, use a Sine wave in the sub oscillator.

Next, modulate the filter cutoff with envelope 1 for dynamic shaping. Finally, in the Matrix tab, set up an LFO with a quarter-note delay to sidechain the amp, giving the stabs a rhythmic, pulsing feel.