Hello Strudel: Wait, I Can CODE Music Now?

I used to click MIDI notes. Now I can code them!

Let’s look at how we can build a Trance beat from scratch.

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Round I: Create The Driving Pulse

Trance is built on “4-on-the-floor.” This means the Bass Drum (Kick) hits on every single beat of the measure: 1, 2, 3, 4.

The Tools:

• Set Tempo: setcpm(138/4), dividing by 4 sets the grid to 138 BPM (Beats Per Minute), the standard speed for Trance.
• The Source: s("..."), short for sound(). It tells the engine to play a sample pattern.
• The Kick: bd, short for “Bass Drum”.
• The Texture: .bank("tr909"), loads the legendary Roland TR-909 drum kit, known for its punchy, mid-range “thump.”
• The Groove: .gain("..."), controls volume. Use this to add Dynamics (changing volume per hit) so the drum sounds human and driving, rather than robotic.
• The Eyes: _punchcard(), generates a piano-roll visualization to verify the rhythm pattern.

Click the Play button below to hear it right now.

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Round II: Add the Energy

A Kick drum alone is a heartbeat. But Trance needs energy. Energy comes from the Off-beat.

If I place a sharp sound exactly in the middle of two kicks, the brain creates a sense of suction, pulling me to the next beat. So let’s use Open High Hat (oh) to create that energy, and the Hat must play only on the off-beats.

The Tools:

• Stack the sounds: stack(..., ...), to layer independent musical parts together.

I did a bit of refactoring to the code, also I tweaked the hi-hat a bit, because Trance relies on a hypnotic, steady machine-gun rhythm. So I made the off-beat hats steady and loud (.gain(0.9)).

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Round III: Add the Anchor

We have the Kick (1, 2, 3, 4) and the Hat (&, &, &, &). Now we need the anchor. It means the Clap (or Snare) on beats 2 and 4.

In Trance, the Clap is never “dry”. A dry clap sounds like a toy. Trance claps sound like they are being played in a massive stadium. We need to add Space.

The Tools:

• cp: Clap
• sd: Snare Drum
• delay(0.3): Controls the amount of echo (feedback). This fills the empty space between the beats.

Pro Tip

Combine delay(0.3) with .room(0.5) to add Reverb. In Trance, I normally shorten the sample using .decay() (making it snappy) and then add Reverb using .room()