Tunefish 3 is a compact virtual analogue synthesizer originally created for the demo scene, specifically for 64k intros by the Brain Control group. Despite its minimal size, the VST instrument version offers an expanded feature set and is freely available to the public. It remains an active project with ongoing development and encourages user feedback to refine its capabilities.

The synth features a unique spline-based oscillator capable of dynamic waveform configuration, complemented by an additive synthesis engine. It goes beyond traditional waveforms like sine, sawtooth, triangle, and pulse by allowing intricate shaping through six control points with step, linear, or spline interpolation. The noise generator is highly flexible, producing noise at any frequency and bandwidth, while multiple filter types including lowpass, highpass, bandpass, and notch provide extensive tonal shaping options.

Tunefish 3 also incorporates a comprehensive modulation matrix with four ADSRs and four LFOs that can be assigned to nearly any parameter. Its effects section supports flanger, chorus, distortion, delay, reverb, equalization, and formant effects, allowing users to chain up to ten effects in any order. This combination of synthesis and processing tools makes Tunefish 3 a powerful yet accessible option for producing a wide range of sounds.