PhaseRings is a musical instrument for performing expressive music with touch gestures. Anyone can create a beautiful piece of music with our sound schemes and generative composition engine!

Each ring on the screen represents a different pitch, and you can tap and swirl on each ring to create combinations of long and short notes. The angle and size of your tap will change the timbre of the notes you create!

PhaseRings includes seven expressive “sound schemes” featuring percussive sounds like marimba and singing bowls as well as pure synth sounds like phase and string synthesis.

Three “compositions” of pitches are included in the app, but you can also create your own custom composition by choosing three base notes and scales, PhaseRings will do the rest, generating a series of great setups from the harmony you choose!

Now available on the AppStore!


BirdsNest is an iPad-instrument recalling the forest sounds of a Northern Swedish summer. Tap and slide to make music with bird calls, percussion sounds, and field recordings and have fun with the built in “auto-play” and looping features.

Metatone Apps on a network will automatically find each other and keep their scales in sync to help perform great improvised music with an ensemble! Every time you press “sounds” or switch one of the functions on or off there’s a chance that your action will be mirrored in the other iPads in the group!

Available now for free on the iTunes App Store!


Metatone Lonsdale is a collaborative musical instrument created for a performance at Everything Nothing Projects at Lonsdale St Traders in Canberra, Australia. Tapping and swiping the screen controls sounds sampled from the venue as well as an array of percussive sounds. Switches control a “looping” function and an autoplay feature that triggers clusters of quiet sounds. The sounds and tonality of the instrument can be shuffled by pressing the “sounds” button.

When multiple devices running Metatone Lonsdale are on the same wifi network, the apps find each other automatically and control each others’ tonality, looping and autoplay switches.

Nordlig Vinter

Nordlig Vinter plays computer generated soundscapes inspired by the landscape of Northern Sweden in winter. This app is now available free in the Apple app store!

The app includes three soundscapes - "Ice Drum", "Snow Bells" and "Clusters" as well as an adjustable reverb effect that processes audio from the device's microphone. These soundscapes can be enjoyed by themselves, or used as backing tracks for musical improvisations, or for Charles Martin's suite of compositions for vibraphone and iOS devices.

The source code for Nordlig Vinter is available on Charles' GitHub page.

Snow Music

Snow Music is now available in the iTunes store for free!

Snow Music is a simple computer instrument created by Charles Martin and Ensemble Evolution for bringing the sound of snow and ice in Piteå into their performances.

Tap the snow to create the sound of footsteps, swipe to create the sounds of sliding in the snow.

Three switches control ongoing musical phrases: haunting bells, evolving cymbals and a snowy winter wind.

All sounds recorded in Piteå, Sweden in February 2012.

Support and Commissions

All support queries should be directed to the contact form on this site or to my Twitter account.

I am available to develop music or sound focussed iOS applications or interactive sound components for other applications using Pure Data, openFrameworks, or Processing. Drop me a line if you would like to work with me!