Waveforms
Every sound you hear is a vibration - air molecules pushing back and forth. A waveform is a picture of that vibration over time. Its shape affects the harmonics in the sound, which gives you a useful starting point when choosing a synth oscillator.
Sound as a Wave
When a speaker cone pushes forward, it compresses the air in front of it. When it pulls back, it creates a gap. This push-pull cycle repeating hundreds or thousands of times per second creates the tone you hear. The shape of that cycle determines the character of the sound.
The Four Basic Waveforms
Synthesisers start with these four fundamental shapes. Each has a distinct sound because of how many harmonics (overtones) it contains.
Sine Wave
The purest tone possible - just one frequency with no harmonics. Smooth and clean, like a tuning fork or a flute-like tone. Used for sub-bass, test tones, and as a building block for more complex sounds.
Square Wave
Instantly on, instantly off - like a switch flipping. Contains only odd harmonics, giving it a hollow, woody quality. Think retro video game sounds, clarinets, and hollow synth tones.
Sawtooth Wave
Ramps up then drops instantly. Contains both odd and even harmonics, so it starts bright and buzzy compared with a sine or triangle. In a subtractive synth, that gives the filter plenty to shape for pads, leads, and basses.
Triangle Wave
Halfway between sine and square. Contains odd harmonics like the square wave, but they're much quieter, giving a softer, more muted sound. Good for gentle bass tones and sub-bass with a bit more character than a pure sine.
Comparing Harmonic Content
The number and strength of harmonics determines brightness. More harmonics = brighter, buzzier sound. Fewer = darker, smoother.
Taller bars = louder harmonics. Sawtooth has the most harmonics, sine has none.
Bonus: Noise
Noise isn't a traditional waveform but it's essential in synthesis. It contains all frequencies at once with no musical pitch - like the static between radio stations.
White Noise
Equal energy at all frequencies. Sounds bright and hissy. Used for hi-hats, snare texture, risers, wind effects, and adding "air" to sounds.
Pink Noise
Less high frequency energy, sounds warmer and more balanced. Used for ocean sounds, mixing reference, and warmer textural effects.
Production Tip
When you open a synth plugin and hear a raw, buzzy sound, that's usually a sawtooth wave. Synthesis starts with simple periodic shapes, then uses filters, envelopes, and effects to change their harmonic content and time behaviour.
Try it
Tap the same pitch through four oscillator shapes. The note stays constant - only the waveform changes.
Same note, same volume, different oscillator shape.
Key takeaway
Sine, square, sawtooth, and triangle are four basic waveform shapes. Each has a distinct harmonic profile, which gives a synth patch its starting spectrum before filtering, envelopes, and effects are applied.
Next: why a piano and a flute playing the same note sound completely different - harmonics and overtones.
Hear waveforms in context
Starts generates arrangements using different synth sounds built from these basic waveforms.