This year I have picked up lots of different gear for making electronic music. Far more than is required to make interesting sounds, but maybe enough for an interesting comparative review.
My output so far is on Soundcloud, as erollins with the frog.
This write-up is from the context of "what is the minimum needed to get started?" And that, in turn, depends on how you want to make the music. Just on the computer? Just with external instruments fed to the computer as a recording device? Or some mixture? Also, live performance? Or pure studio composition? And even in the studio, "live" recording versus note-at-a-time entry?
All the above options start with DAW, Digital Audio Workstation, software. This software both drives and records external hardware and internal software (VST plugins) instruments. It provides a MIDI piano-roll interface for composition, and often comes with its own libraries of recorded sounds and MIDI software instruments. There are two basic styles of DAWs, Ableton-style versus the rest. DAWs were originally created for studio recording and composition, but Ableton Live pioneered a DAW design that could be used in live performance. Rather than just pressing PLAY on a single track (instrument) or all the tracks in the "Arrangement View", Ableton Live allows the creation of short "Clips" that can be independently triggered (on the correct downbeat!) within the "Session View". This way a live musician using the DAW for accompaniment can choose when to move to different sections of a song (chorus vs verse, etc.) rather than being locked to a prerecorded linear sequence. Numerous hardware devices have been created to control this triggering (such as the upper buttons on the AKAI APC Key 25) to avoid the use of the computer mouse during performance. The downside of having two different modes and interfaces (Session versus Arrangement view) is the additional complexity of the interface when only doing studio work. OTOH even in the studio live clip launch sequences can be recorded -- this is how I created "Polyplexed" in Bitwig Studio.
Bitwig Studio is a much more recent DAW, created by ex-Ableton employees, that also follow's Ableton's clip launching design. It has some support for third-party clip launching hardware (AKAI APC Key 25), and also supports using the Microsoft Surface Book touchscreen as a launcher. Bitwig also does the best job of sandboxing VSTs -- the Twist synthesizer insists on shrinking its display because it doesn't understand high-(retina/4K)-resolution, and only Bitwig prevents it from messing up the entire DAW. It may also provide better CPU isolation between VSTs, though it may itself be more of a CPU hog. Haven't diagnosed the periodic mysterious live audio pops I get, though they are not making it into the recordings.
PreSonus Studio One is a more traditional DAW which does not do clip launching. It provides more facilities useful for recording and mastering rock-band music.
All 3 DAWs come in intro/demo versus full versions. The intro "Ableton Live Lite" is free with many hardware devices such as the AKAI APC Key 25. The full versions of all three come with reasonable integrated MIDI software synthesizers and sampled sound sets (drums, pianos, etc). The full Ableton Live Suite comes with the most sounds and instruments (though some are legacy redundant) and is the most expensive ($749 full, $649 with upgrade from Lite). The other two full version DAWs are about half as expensive.
When making electronic music everything besides the DAW is optional. Some artists such as deadmau5 appear to compose whole songs purely using the computer keyboard or mouse for note-by-note entry into the piano roll and plunking the on-screen virtual piano keys. Alternately any MIDI keyboard (today MIDI over USB) can be attached to the computer for note entry.
A real analog synthesizer such as the Moog Sub 37 will only have analog outputs. Recording this output on a computer will require analog-to-digital conversion using an audio interface. I chose the Native Instruments Komplete Audio 6 because besides analog inputs and outputs it provides digital output, and my audio amplifier only accepts digital inputs. The Roland System-1m is a digital emulation of an analog synthesizer, and provides USB digital audio output. Ableton could handle USB digital audio input, but Bitwig studio requires all external inputs pass through an audio interface so I had to use the analog output of the Roland. Also once an audio interface is being used for audio input, it must also be used for audio output.
Originally analog hardware synthesizers were "modular": each function (oscillator, filter, etc.) was a separate physical module, and these were externally wired together using physical patch cords. Any keyboard was also a separate add-on, and pre-MIDI used CV (Control Voltage) plus Gate for control signals. Later analog synthesizers integrated all the modules plus the keyboard into a single physical unit, with most of the connections internal and hard-wired but with a digital subsystem that supported saving configuration information. These saved configurations were called "patches", and included both factory settings and user saved settings. Many songs are created simply using factory patch (preset) sounds, while others involve creating entirely new sounds or varying existing sounds by twisting the knobs while playing. This live knob twisting is how I created "All The Knobs" on the Moog Sub 37.
Analog modular synthesizers are making a comeback in a new smaller rack format -- the Eurorack standard. The Roland System-1m, while an all-digital unit that supports patches and downloaded emulation of classic Roland analog synths such as the SH-2, does provide analog input and output of various patch points so it could be integrated into a Eurorack system.
Native Instruments Reaktor is a software synthesizer construction kit that runs as a VST plugin inside a DAW. It has been used to create many different interesting (sold separately) synthesizers, such as the Polyplex drum sampler I used in "Polyplexed". Originally creating your own synthesizer using Reaktor was quite complex, involving a visual programming environment plus scripting language much like National Instruments LabView for scientists and EEs. Recently the new Blocks layer was added, resembling a set of Eurorack modules. This makes creating new synthesizers much simpler, and looks like a fun way to both learn visual programming and create music. The examples are also playable out of the box, and the online user community is creating more Blocks. Reaktor instruments (such as Polyplex) can consume a ridiculous amount of CPU, even shutting themselves down when run on the Surface Book laptop instead of a high-end desktop, but this can be improved by reducing the sample rate. One other caveat -- I wouldn't try to figure out "what is a synthesizer" starting with Reaktor or most Reaktor-based synths.
The Moog Sub 37 does traditional analog "subtractive" synthesis, and the Roland System-1m emulates the same. Other types of synthesis include additive, FM, and wavetable. I have been trying other interesting software synthesizers with these techniques, including Native Instruments (Reaktor) Rounds, Future Audio Workshop Circle2, Xfer Records Serum, and Ableton Live Studio's Operator. Also Sonic Charge Microtonic for drums.
My first purchase was the Roland System-1m, and I learned some by twisting its knobs, but I learned a lot more from the Moog Sub 37 because it comes with a real manual. Both have a traditional left-to-right subtractive synthesis architecture with 1 or 2 LFOs, 2 oscillators, mixer, filter, amplifier and filter ADSR envelopes, and amplifier. In a software synthesizer it is probably easiest to learn one that mimics this architecture. Ableton Live's Operator has a different layout and is FM, but Ableton has the best tutorial of the three DAWs including an Operator tutorial (Operator comes as part of $749 Live Studio, or is available as a $99 add-on to Live Lite). The Mai Tai synth in Studio One looks the most conventional (i.e. resembling the knobs and layout of a hardware synth), while Polysynth and FM-4 in Bitwig are closer to Operator in appearance (and probably too basic). Another conventional-appearing synth is AIR Hybrid 3 (came free with AKAI APC Key 25). Others "close enough" may be Circle2 and Serum. Lots of other companies sell conventional-appearing software subtractive synthesis VSTs, but I haven't tried them since I already have the hardware. I was actually more interested in "unconventional" software UI presentations such as Circle2 and Rounds, which aren't bound to emulate a physical faceplate.
All the DAWs provide digital audio effects such as compressors, delay, and reverb that can be added to each track. This is great for recording, but in live performance requires feeding the audio into a computer with the DAW. For a pure-analog performance (fed directly to a powered speaker like a QSC K-10) analog guitar effects pedals can actually be used. I used a Moog MF Delay pedal on "All The Knobs". With an attached expression pedal the last note can be "trapped" to resonate indefinitely inside the MF Delay.
USB MIDI input devices include keyboards and drum pads. Keyboards with traditional MIDI outputs can also be attached to keyboardless synthesizers like the Roland System-1m, and keyboards with CV/Gate outputs can be attached to old-school Eurorack modules (though I wasn't able to get the CV/Gate output of the AKAI MAX 49 to work with the CV/Gate input of the Roland System-1m). The AKAI APC Key 25 provides 2 shiftable octaves of keyboard (too small for live performance, but fine for composing) plus 8 tracks * 5 scenes of Ableton clip launching, plus 8 mappable knobs (I used a mapped knob to vary the BPM in "Polyplexed"). The AKAI MPD 226 provides a 4x4 drum pad grid plus mappable knobs. It has pre-programmed and user-programmable mappings of the pads to entries in the different DAW drum racks, which is very useful because every DAW maps the drums to different MIDI notes (sometimes even differing between drum kits in the same DAW).
1) Decide on live performance versus studio-only.
2) Choose input device (hardware synth keyboard, USB MIDI keyboard, or only computer keyboard plus mouse).
3) Pick a DAW.
4) Did (2) or (3) come with a simple synth? If not, pick a VST synth.
5) Make some music.