The part that usually goes wrong
Most plugins that claim microtonal support convert a note number to a frequency in one place and then do it again, differently, somewhere else. The oscillator is in your scale and the sub is not. The glide lands on a twelve tone target. The sequencer transposes by semitones through a scale with no semitones. You end up with an instrument that is microtonal in the demo and twelve tone in the details.
Getting this right is not a feature so much as a sweep. Every place in the instrument that turns a note into a pitch has to ask the same question of the same source, including the ones you forget: portamento targets, unison detune, the sequencer, per oscillator transpose, retuning under a note that is already sounding. That sweep is what shipped in Laura, rather than a tuning page bolted to the front.
What that means in a session
Load a master, pick 22edo or a just intonation lattice or your own Scala file, and play. The footer names the scale that is currently active, so you can see at a glance that it was picked up rather than guessing from the sound. If the scale has fewer than twelve notes to the octave, the notes with nothing to map to are filtered rather than silently doubled onto a neighbour.
Coarse transpose moves by one step of whatever scale you are in. Fine stays in cents, because cents remain meaningful when steps do not. Concert A is a global setting in the footer, so an ensemble at 432 or 415 is one number rather than a per patch chore.
On an MPE controller the tuning table is kept per channel, so two notes held at the same time can sit in different tunings. That matters for adaptive just intonation, where the tuning of a note depends on the chord it is in.
What Laura does not do
It has no scale editor of its own, and it will not read a .scl or .tun file directly. If you have no MTS-ESP master in the session, Laura is an ordinary twelve tone instrument. That is a deliberate division of labour: the master owns the tuning, every client follows, and there is exactly one place to change your mind.
If you would rather it read scale files on its own, say so. This part of the instrument exists because a microtonal composer asked for it and then told me what was still wrong with the first attempt.
The rest of the synth
Tuning is the reason you might be on this page, but it is not the instrument. Laura is a polysynth with four engines in one signal path: wavetable with a built in editor, FM, classic analog, and fractal oscillators that read their waveform out of a Mandelbrot or Julia set. Around them sit a sixteen slot modulation matrix, an eighteen device effects rack, a four mode sequencer and 309 factory presets.
Hear it
Showcase
Every part played by Laura. Standard tuning, for what it is worth.
Try it against your own master before you spend anything. Buy Laura for $69 when it holds up. One payment, lifetime license, free updates.
Questions
Does Laura support MTS-ESP?
Yes, as a client. Load any MTS-ESP master in the session and Laura follows it with no routing and no files to import. If no master is present it behaves as a normal twelve tone instrument.
Can I load a Scala file directly into Laura?
No. Laura has no scale editor and no .scl or .tun import of its own. It takes its tuning from an MTS-ESP master, which is where your scale files live. That is a deliberate split: one place defines the tuning, every instrument follows it.
Do held notes retune when I change scale?
Yes. A master can change the tuning under a sounding note and Laura follows it while the note rings, rather than waiting for the next note on.
Does it work with MPE?
Yes, and the two combine. On an MPE rig Laura keeps a tuning table per channel, so notes in the same chord can sit in different tunings.
What happens to the transpose knobs in a non twelve tone scale?
Coarse transpose moves by a scale step, not by a twelfth of an octave. In 22edo, one step of coarse is one step of 22edo. A knob that moved by a semitone would be meaningless in a scale that has no semitones.