Guest article by Roger Linn about exploring LinnStrument Y-axis
Inventor of LinnStrument: Roger Linn
James Weaver’s most recent article entitled Domo Arigato Tempo Rubato contains an overview of musical expression and some corresponding expressive capabilities of LinnStrument. That article includes a brief discussion about making expressive variations in timbre on LinnStrument by moving your fingers along the Y-axis. James reached out to me to shed additional light on Y-axis expressiveness.
For LinnStrument and other expressive instruments, the value of sensing finger pressure (Z-axis) and left/right (X-axis) movement is pretty clear: pressure controls note loudness and left/right movement controls pitch variations. However, many people are somewhat flummoxed by the concept of controlling timbre via forward/backward finger movements (Y-axis) within one of LinnStrument’s 200 note pads.
What’s timbre? Pronounced tam-ber, it is defined by Oxford Dictionaries as…
“the character or quality of a musical sound or voice as distinct from its pitch and intensity”
In the context of LinnStrument, timbre refers to variations in tone, all of which are musically useful at any note loudness or pitch. For example, bowing a violin near the bridge results in a sharper tone than bowing near the neck. Or the tone of a flute can be changed by mouth position or a sax by bite pressure. Taken together, a skilled performer’s subtle control of loudness, pitch and timbre is a big part of what makes a great instrumental solo great.
Here’s a video I made that demonstrates real time variation in loudness, pitch and timbre, using the Polysynth instrument in the new version of Bitwig Studio coming this summer:
In this video, finger pressure controls a combination of volume and filter frequency, left/right movement controls pitch, and forward/backward movement controls the timbre of the sound source, which in this case is a pulse wave oscillator. Notice how the timbre changes from thin to full as I move my finger forward and backward, and how the combined variation in loudness, pitch and timbre makes the sound very expressive. Now consider that what you’re hearing is the simplest synthesizer possible, consisting merely of an oscillator, filter and volume control and nothing else. This would sound roughly like an old telephone dialtone when played from a regular MIDI keyboard’s on/off switches.
So what can you control with the Y-axis? Ideally you’ll want to use it to vary the fundamental timbre of the source waveform. If you know a little about MIDI and synthesis, LinnStrument normally sends Y axis information using MIDI Control Change 74 messages. Here are some ideas for how to control timbre in your sound generator from these CC74 messages:
- For basic analog synthesis, modulate the pulse width of a pulse oscillator. This changes the harmonic content of the pulse waveform between a thin and full tone. If you have Logic Pro X, you can hear what this sounds like. Download our LinnStrument project file from the LinnStrument Support > Getting Started page. Set your LinnStrument to the “One Channel” settings described in section 4 of that page, then select the track in the Logic file entitled “Simple 3D Pulse Synth”.
- Also for basic analog synthesis, modulate the level of hard oscillator sync, which creates dramatic changes to the timbre.
- Additionally for basic analog synthesis, assuming you’re using pressure to modulate the filter frequency, use the Y-axis to modulate the filter resonance.
- For sampling, you can’t change the fundamental timbre of a sample, but you can use the Y-axis to vary the balance between two or more source samples. For example, one could be a soft sax tone and the other a harsh sax tone. Or one could be a sax sound and another a violin sound.
- For FM (frequency modulation) synthesis, use the Y-axis to vary the frequency of the modulating oscillator, which changes the timbre of the carrier oscillator.
In summary, using the Y-axis to vary timbre during performance adds a lot of expression and emotion to your musical performance. Given that nature has graciously given this particular universe three dimensions, why not use them all?
Regards,
Roger Linn
Roger Linn Design
Cultured Ear 