Pitch

What Is Pitch?

In synthesis, pitch is the perceived frequency of a sound – how “high” or “low” it feels. Technically, it’s how many cycles per second (Hz) the waveform is oscillating. For example, a sine wave at 440 Hz = the A above middle C – aka A4 in Western tuning.

When we talk about pitch in modular, we’re usually talking about how to control it using control voltage (CV). That’s where the volt-per-octave (V/Oct) standard comes in.

Volt-per-Octave (V/Oct) Explained

  • 1V = 1 Octave: Every time you increase the pitch CV by 1 volt, the pitch doubles in frequency – that’s one octave up.
  • Linear scaling: 0V might be C0, 1V = C1, 2V = C2, etc.
  • Fine tuning: Notes in between (like C# or F) are fractions of a volt – most quantizers divide 1V into 12 steps for semitones.

Why It Matters

  • Let’s you control oscillators melodically with sequencers, keyboards, or CV sources.
  • Good V/Oct tracking means your oscillator stays in tune across octaves.
  • You can transpose patches just by adding/subtracting voltage.

A Quick Note on 440 Hz

In most Western music systems, A4 (the A above middle C) is tuned to 440 Hz. This became the standard reference point for tuning instruments – and synths often default to this pitch when zeroed out. If your oscillator is tracking properly, sending 3V might land you right on that A5 (880 Hz), depending on your base tuning.

Pitch might seem simple, but it’s the foundation for everything melodic. And in Eurorack, it’s one of the most powerful things you can control with voltage.

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