LayR first arrived in March last year and has been consistently well received. The app is described as “a massively polyphonic, multi-timbral synthesizer for iOS devices, optimized for modern 64 bit CPUs and capable of delivering up to 256 voices of rich, multi-layered and textured sounds”.

LayR’s primary sound components are called Performances where a Performance is a set of Instruments and each Instrument is a set of Layers and each Layer is a complete synthesizer. A performance can consist of any number of instruments each with its own MIDI channel and crossfading keyboard span. Each Instrument can consist of any number of Layers to a maximum of 128.

Whilst the latest version of the app hasn’t added anything radically new, it has made a lot of changes that make it easier to use and improve the overall user experience. Here’s what’s new:


  • Macro Control Panel: A new panel that lets you change assigned synth parameters globally across an entire performance.
  • Link Assign Panel now has an extra section for assigning Layer parameters to Macro controls.
  • You can now assign any MIDI controller to Instrument Volume Sliders. ( defaults to cc 7 ).
  • Load Preset panel now updates it’s selection if a MIDI bank or program change is received while it’s visible.
  • New option in settings: Don’t Start Voices When Volume is Zero: Prevents voices being started if Instrument or Layer volumes are zero.
  • New option in settings: “Multi Out: FX Only in Stereo Output”, converts the IAA Stereo Mix output to an effects return if any of the 8 aux audio outputs are in use.
  • Dials will now always show at least 1 degree of coloured arc unless their value is equal to zero.
  • Increased fall time for peak hold metering in master strip.
  • Updated PDF manual.

Bug Fixes:

  • Fixed a common crash during audio unit initialisation.
  • Fixed crash when long pressing on A to B range buttons.
  • Fixed: Potential crash when saving performances if poly aftertouch is assigned.
  • Fixed: Audio Unit now respects all persistent preferences set in the IAA app.
  • Fixed an audio spike when an AU is loaded in a certain state from a host. Could cause a loud reverb explosion.
  • Fixes a rare problem where an AU host could start to load a preset before the Audio Unit had completed initialisation.
  • Fixed: Current bank is now properly set when selecting a bank in the load preset panel.
  • Fixed a state where MIDI controller values for the CC Mixer would fail to be loaded from a saved preset.
  • Fixed: UI crash when tapping on AB-Range modifier tempo button after previously setting time to maximum ( 100s ).

LayR costs $25.99 on the app store