System 50:50 in Sound

What is System 50:50 in Sound?

System 50:50 in Sound is a simple yet radical method for ensemble improvisation, developed by Phil Morton over twenty years.

In its simplest version:

• The improvisation has a fixed duration.
• Each performer must play for 50% of the piece’s duration and remain silent (tacet) for the remaining 50%.
• These durations are aggregate totals, not fixed blocks of time.

For example, in a 16-minute piece each player plays for a total of 8 minutes and is silent for 8 minutes. They are free to choose when they play and when they are silent, as long as the final balance is 50:50.

Each player has their own clock (typically a mechanical chess clock with two displays — one for “play” and one for “tacet”) to manage their contribution. They retain full agency over the sounds they make during the periods they choose to play.

The method is deliberately simple, versatile and flexible. It can be applied to ensembles of any size, though its potency becomes especially clear with larger groups (from eight players upwards).

Three attributes can be varied each time the system is used:

• The number of players
• The ratio of tacet time to free-play time
• The overall duration of the piece

What results is music shaped as much by silence as by sound. Ensemble density shifts moment by moment. Active listening becomes the primary compositional force. The music creates itself.

The Aim

The aim of System 50:50 in Sound is to create something new in a musical sense — something owned by those present — by exploring the possibilities and the limits of freedom and improvisation in music-making.

The approach is threefold:

• Introduce silence into the ensemble sound
• Shape the ensemble size, moment by moment
• Empower the musicians with agency to shape the music through both sound and silence

In essence, System 50:50 is a form of composition whose primary function is to create a space — specifically, a space shaped by silence.

Free improvisation in large groups has long been recognised as difficult. As the London Improvisers Orchestra has observed, the larger the group, the harder it becomes to create a collective improvisation that is effective and allows space for everyone. Simon Fell noted that improvisation in large ensembles multiplies all the difficulties and uncertainties of the practice. Tim Hodgkinson has remarked that pure free improvisation works beautifully in small groups but becomes very hard above a certain number without some form of limit.

System 50:50 offers a response to these challenges. It introduces a clear, egalitarian constraint that still leaves musicians with genuine agency. The result is music that is less competitive, more cooperative, and often more open and dynamic than conventional large-group free improvisation.

Who is it for?

System 50:50 works with:

• Any number of players
• A wide range of experience
• A wide range of technical and instrumental abilities
• Neighbours and strangers alike

It supports the creation of music without prior preparation. Experienced improvisers can use it immediately — “straight out of the box.” For less experienced players it provides a supportive, democratic framework that removes the pressure of constant playing, reduces the influence of ego or virtuosity, and creates room to think and to listen.

It can serve as a stepping-stone into free improvisation, or it can be approached as a distinct aesthetic with its own sound and attributes. Regular users often come to hear it as a new form of ensemble music in its own right.

In short, it is open to experienced musicians and amateur enthusiasts who play any instruments. No previous free-improvisation experience is required.

About Phil Morton

Phil Morton has been active in free improvisation as a player, promoter and teacher since 1998 (and as a listener since 1968). He developed System 50:50 over twenty years. He describes it as “a gift that keeps on giving” — a simple method that unpicks the complexity of large-group free improvisation while leaving musicians with genuine agency.

Practical details

• Venue: Fishermen’s Chapel, Leigh-on-Sea, SS9 2EA
• Cost: FREE
• Instruments: Any
• Experience: All levels welcome
• RSVP: musicworkshops@konsztruktingsoundz.co.uk (Mandatory!)
• Four sessions in 2026:

• • Saturday, 26th September 2026, 2:30PM – 4:30PM – afternoon session as part of Konsztrukting Soundz EVENING TWENTY-SEVEN, Facebook event here https://fb.me/e/jQCWAjqQj
  • Saturday, 17th October 2026, 2:30PM – 4:30PM – afternoon session as part of Konsztrukting Soundz EVENING TWENTY-EIGHT
  • Saturday, 14th November 2026, 2:30PM – 4:30PM – afternoon session as part of Konsztrukting Soundz EVENING TWENTY-NINE
  • Saturday, 12th December 2026, 2:30PM – 4:30PM  – afternoon session as part of Konsztrukting Soundz EVENING THIRTY.

What participants say

“It gives me permission to do nothing.”

Jon Aveyard