Surge XT: an excellent, free, open-source, MPE synth

And the official LinnStrument synth

Surge XT is my new favorite synth and the new official synth for LinnStrument. Unless I need samples, it's my new go-to synth. Why?

* Extremely versatile, enabling highly complex and beautiful sounds
* MPE compatible
* FREE and open source
* Runs on Mac, Windows and Linux, both as a plug-in and as a standalone app.
* 2 "scenes" (voice partials), each containing 3 oscillators and 2 multi-mode filters
* Highly versatile oscillators: classic, wavetable, FM, a unique variant of wavetable called "window", Karplus Strong string synthesis, additive, and more, all with a wide variety of ways to modulate the timbre, ideal for LinnStrument's Y-axis control.
* Just about everything can be modulated by just about everything, and in a simple and intuitive way.
* Lots of effects: delay, reverb, chorus, distortion, rotary speaker, EQ, compressor/limiter/expander, frequency shifter, vocoder
* The Distortion effect has pre- and post-EQ, good for guitar amp simulation.
* The manual is easily accessible from the panel's "menu" button. Why doesn't everyone do this?

Surge is maintained by a group of talented coders, but was originally created by Claes Johansen, the principal creator of Bitwig Studio and one of my favorite music software creators. So the fundamental architecture is well-designed and extremely capable.

Download Surge and play my "LinnStrument MPE" library of sounds: 

1) Download Surge XT from here and install it.

2) The default appearance of Surge XT doesn't look so pretty to my eyes. To change it to look like the picture above, click Surge XT's "Menu" button in the lower-right corner of its panel, then select "Skin Library...". Then download the "Royal Surge XT" skin folder. Then click the MENU button and select "Install a new skin..." and navigate to the downloaded folder to install it. Finally, close and reopen Surge and click the MENU button again to select "Skins", then select the new "Royal Surge XT" skin.

3) Set your LinnStrument for MPE play: In Per-Split Settings > MIDI Mode column, hold "ChPerNote" for 1 second to change all needed settings for MPE play.

4) To bypass any initial MIDI channel confusion with your DAW, I recommend starting by using the standalone Surge XT application. Start the application and turn on the "MPE" button in the top middle of its panel. Now all of Surge XT's built-in sounds are MPE-compatible, permitting polyphonic pitch slides and performed vibrato. However, these sounds are optimized for MIDI piano keyboards so most won't respond to pressure or Y-axis. To hear MPE sounds optimized for LinnStrument's pressure and Y-axis control, look in the "Third Party Patches" category for the "LinnStrument MPE" folder. The sounds in the "Winds" subfolder created by "thoughtForm" respond particularly well to LinnStrument's three dimensions of touch.

Here's a video in which I demonstrate some of the "LinnStrument MPE" sounds:

Here's a video I made called "Creating LinnStrument MPE sounds in Surge XT":

And here's a video called "MPE Sound Design in Surge XT: Initial Patch", created by "ThoughtForm", who created many of the best sounds in the "LinnStrument MPE" library in Surge:

Care to contribute to the library?

If you're skilled at creating good MPE sounds, please email any good ones to me for possible inclusion in the "LinnStrument MPE" library. In general, I'm looking for sounds that LinnStrument players value most, as suggested by the sounds they use in their videos. In general, these are rich, complex sounds with an acoustic or natural quality. Though LinnStrument videos often use samples, Surge is not a sample player. However, it does have extensive capabilities for complex acoustic-like sound sources.

In general, try to create sounds that are complete and expressively playable musical instruments. Here are some suggestions:

* Focus on sounds intended for LinnStrument's focus on playing expressive notes and chords, instead of sound effects, sequences, highly dissonant sounds, sounds swimming in effects, or sounds intended to produce an entire soundtrack by holding down one note.
* Make sounds that use LinnStrument's advantages over a standard MIDI piano keyboard. For example, sounds that only use velocity and envelopes without any pressure or Y-axis response aren't so useful because any traditional synth sound in Surge's other libraries can do the same thing with the MPE button turned on.
* Use rich, complex, acoustic-sounding timbres instead of simple, buzzy oscillator waveforms.
* Though Surge is not a sample player, you can embed a wave file into a patch for use either as a short one-shot sample at the start in combination with other generation methods, or by using Y-axis as an index into the wave file to produce a continuous variety of timbres. The sounds by "thoughtForm" in the Winds folder are excellent examples of this.
* Use pressure or velocity to control harmonic content as well as volume, for a more natural dynamic reponse.
* Use Y-axis to vary timbre by altering the waveform in some way instead of merely controlling filter frequency. In consideration of LinnStrument's short Y-axis range, Y-axis timbral changes should be subtle and usable in all positions, changing timbre without changing apparent volume.
* Fine-tune your velocity, pressure and Y-axis response, throughout the pitch range, such that a skilled player would find it useable to produce a quality musical performance in all pitch and loudness ranges.
* Don't use too much reverb or other effects. Many people don't know Surge well enough to remove reverb, but anyone can add reverb outside of Surge. That said, light reverb serves well to augment a sound.
* Maximize the output volume so that the output meter is at full when playing a chord or forcefully-played solo sound, such that switching between sounds in the LinnStrument MPE library maintains a similar volume.
* Try to avoid making sounds that are simple and ordinary, useful only in narrow cases, or very similar to sounds that already exist in the LinnStrument MPE library. The goal is for all sounds in the library to be quality, useful, valued, distinct from other existing sounds, and such that user feel they don't have to search through many unuseful sounds in order to find a few good ones. I'd prefer to have a small number of high quality sounds.
* Use short, descriptive names that people will find most helpful in finding the sound they're looking for. Don't use non-descriptive joke names or long names that might not fit in the patch display.
* If there's anything that would be helpful for the user to know in order to get the most from the sound, put it in the patch comments.
* For ideas and to learn the many techniques in Surge, try looking into the current sounds in the LinnStrument MPE library to see how they were created, as well as other sounds in Surge's factory patches.
* You can repurpose one of Surge's LFOs to act as a Pressure Response Curve, permitting any curve between linear and exponential pressure response. Click here to learn how to do it.

In the sounds created for the library so far, we certainly don't achieve all of the above goals, but I feel that my stated goals for this library are appropriate for LinnStrument players. Note that if a sound doesn't fit the goals of this library, it's still a good sound for a different library, or perhaps the Surge team would like to add it to their Third Party Patches.