Two interesting Windows VST plug-ins hit this week. First up, Sonata, a rather nice “tone synth” for leads and pads and such has become free. (via our friends at rekkerd.org),) CPU hungry, so this looks like yet another chance to dial up some interesting sounds, throw them in the mix, and bounce. Tetra may be built in SynthEdit, but the engine is coded in C++, and features bandlimited quadrature. What, no bandlimited dodecature? Translate that one for us: “a stereo signal whose harmonics differ pairwise by 90 degrees. By morphing between two definable timbres, Tetra can create a wide range of unique sounds.”