Tone Generation

matrixsynth has posted a series of links to a series of .mp3's detailing the history of electronic music from around the globe.
There are 12 in total.

Synth Drone

Another good sound from audio cookbook. This one was created by programming a single note in a DAW assigning that to a VSTi synth and then setting up some of the parameters to be controlled by MIDI cc in realtime.
The output of the synth was processed using compression, delay and chorus.

The result is a pretty ominous drone sound with some nice sweeping textural changes that could be used as either a piece of atmospheric sound design or the basis of an electronic music track.

synth drone sound

free synth

kx77free has released a fairly comprehensive VST synth that uses a combination of subtractive and additive synthesis. The features list contains some useful features, like plenty of envelopes and LFO's, 2x filters and the like.

Features:

Full parameters controls to make Additive Waveforms with no aliasing.
Full 32 bit High Quality Waveforms.
Same quality for all clock frequencies: 44.1 khz to 192 khz.
independent WaveTracer engine: KxWaveTracer.exe.
Stereo routing.
All modulations are pre-connected, no cables on the GUI.
3 Polyphonic EGs with for each segment: curves, velocity and Kbd controls.
1 Monophonic EG with for each segment: curves, velocity and Kbd controls.
Multiple trigger sources and sync for the EGs and the LFOs.
2 Oscillators with 2 waveforms and 2 outputs with Phase modulation and Sync.
2 independent Sub Oscillators.
2 Monophonic LFOs with 2 Rates and ASR EG.
2 Mulitmode VCFs.
Mixer with 6 sources: Noise, Vco1 1-2, Vco 2 1-2, Ring, Vco1 Width, Vco2 Width and 3 outputs: VCF1, VCF2, VCA.
Each mixer voice can be modulated by different sources.
Noise Generator with an EQ.
Sample&Hold.
Ring Modulator.
6 host sync clocks.
2 Midi inputs.
1 Distortion.
2 Delays with sync, multimode filter and modulation oscillator with sync.
Full NRPN implementation: More 500 parameters.
128 presets

free synth

DSK music has released a little freeware synth that amongst the usual facilities has a pretty neat modulation matrix.

features:

- 2 OSC with 6 waveforms
- Amp. Envelope
- Octave & finetunning
- Advanced pulse modulation
- 2 LFO with 6 waveforms
- 2 Filter (4 modes)
- Osc 1/2 Balance
- Osc sync
- Velocity response knob
- OSC & Filter route
- 7×14 Matrix panel
- 3 Effects: Chorus, Reverb & Drive

a mod matrix is a really useful addition to any synth and can really help you to create interesting sounds.