Monophonic Synth - Online Play with Oscillator & Envelope

A monophonic synthesizer plays only one note at a time. Unlike polyphonic synths that can play chords, monophonic synths excel at lead melodies, basslines, and expressive solo lines. Classic examples include the Minimoog, ARP Odyssey, and Korg MS-20. The single-voice design allows for richer timbral shaping per note.

Sine wave — Pure, smooth tone with no harmonics. Ideal for sub-bass, flutes, and soft pads.
Square wave — Hollow, clarinet-like tone rich in odd harmonics. Great for retro game sounds and punchy leads.
Sawtooth wave — Bright, buzzy tone containing all harmonics. The classic lead synth sound, perfect for strings and brass.
Triangle wave — Softer than square, with fewer harmonics. Works well for mellow leads and flute-like timbres.

ADSR stands for Attack, Decay, Sustain, Release — the four stages that shape a sound's volume over time:
Attack — How quickly the sound reaches peak volume after a key is pressed.
Decay — How quickly the volume drops from peak to the sustain level.
Sustain — The volume level held while the key remains pressed (a level, not a time).
Release — How long the sound takes to fade to silence after the key is released.

A low-pass filter removes frequencies above the cutoff point while allowing lower frequencies to pass through. Lowering the cutoff darkens the sound by removing harmonics. Resonance (or Q) boosts frequencies near the cutoff point, creating a distinctive "squelchy" or "vocal" character. This is one of the most expressive tools in subtractive synthesis.

The on-screen piano shows key mappings. Generally, the bottom row of your keyboard (Z through /) plays white keys, and the home row (S, D, G, H, J) plays black keys. Use the Octave +/− buttons to shift the playable range. Click the piano keys directly for touch/mouse input.

Glide (also called portamento) makes the pitch slide smoothly from one note to the next instead of jumping instantly. The glide time controls how long the slide takes. Set to 0ms, notes change immediately. Higher values create a pronounced sliding effect — a signature sound of many classic monophonic synthesizers.