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An Intro to TwoTone

By Hugh McGrory, Co-founder at Sonify, data sonification and emerging technologies for social impact |


TwoTone lets you turn data into sound and music. It uses the process of sonification to let you hear data. It’s free and open-source and runs 100% on the web, so you don’t need to download anything. TwoTone works on desktops, tablets and phones. It’s designed to be fast, fun and easy to use. TwoTone is imagined by Datavized with support from Google News Initiative.

Official site:
Official app (NEW LINK):
Github repo:

Welcome to TwoTone
TwoTone Web App:

What is TwoTone for?

There are two areas where TwoTone adds value:


Here’s some examples (visit to learn more)

Basque Country EUSTAT ‘Song of the Day’

Datavized collaborated with Basque Country EUSTAT to create a sonification with TwoTone using Basque Country EUSTAT ‘Use of Time’ data from survey data collected in 2013.

About the Data

Basque Country EUSTAT Use of Time

Average Social Time per Participant and Rate Type of Physiological Need Day of the Week and Province

Listen to the Data

Watch the Playthrough

Watch the Tutorial

Remix the Project

To replicate or remix the project, download the ‘Use of Time’ data set here or go to the source link here.

Temperature of the U.S. Economy 1949–2028

This example features a sonification of the U.S. debt to GDP ratio, yearly from 1949–2028. The data used is from the Congressional Budget Office Budget & Economic Outlook Report published January 28, 2019.

Listen to the Data

Watch the Playthrough

View more examples at

How can your organization benefit?

TwoTone is designed to be seamlessly integrated into the workflow of a newsroom and used either as a standalone tool for publishing sonification on the web or as a soundtrack builder for multimedia projects. The tool is fully customizable to enable creators to map any data input to the desired audio output.

What kind of data can I use?

TwoTone will handle files up to 20MB in size and 2,000 rows of data. Formats supported are: .xls, .xlsx, .csv, .ods. Drag and Drop files into the browser window. Remember that your output will only be as good as your input, so please take time to check your spreadsheet for errors or unnecessary text fields. Also make sure that you are uploading an actual spreadsheet and not a PDF since a PDF will not be readable.

Text to Speech

Twotone uses Google’s Text-To-Speech API so that a creator can type a title for their piece and have it read in a male or female voice in different languages. This audio is placed before the music starts to give context to the listener. You can turn it on or off. Being pedantic, this means that Twotone can’t really be described as ‘sonification’ since that word refers to “the use of non-speech audio to convey information or perceptualize data”.

How does it work?

1. Get Data

Select a Data set from one of our samples or Upload one of your own by simply dragging it in.

2. Audio Track

TwoTone will automatically generate an audio track from your data set. You can change your track’s data source or instrument.

3. Play Audio

Click the Play button to hear the sound generated from your data.

4. Speak Title

Enter a Title to automatically generate text-to-speech, toggle to turn speech on or off. Customize settings for language, gender and voice options.

5. Add Audio Track

Generate another audio track automatically from your data set or upload an audio track of your own.

6. Adjust Duration

Adjust your total duration, row duration, and tempo (BPM) to speed up or slow down your composition.

7. Advanced Features

Adjust the volume of your audio track, filter it by data columns or by value, change the key of your musical scale, or adjust octave, scale range and tempo to create an arpeggio.

8. Export Audio

Export your project to an audio file in MP3 or Waveform (PCM) format

MP3 Bit Rate export options are 64 kbps, 128 kbps,, 192 kbps, and 320 kbps.


The inspiration for Twotone came from a 2016 TED talk by Wanda Diaz Merced “How A Blind Astronomer Found A Way To Hear The Stars”.

We developed early ideas for Twotone while we were building Morph. Brainstorms with computer artist and generative composer Glenn Marshall led us to examine some techniques that had been used in the past, like the musical dice games. Here’s a description from Wikipedia:

“A Musikalisches Würfelspiel (German for “musical dice game”) was a system for using dice to randomly ‘generate’ music from precomposed options. These ‘games’ were quite popular throughout Western Europe in the 18th century. Several different games were devised, some that did not require dice, but merely ‘choosing a random number.’The earliest example is Johann Philipp Kirnberger’s Der allezeit fertige Menuetten- und Polonaisencomponist (German for “The Ever-Ready Minuet and Polonaise Composer”) (1757 [1st edition; revised 2nd 1783]). Examples by well known composers include C. P. E. Bach’s Einfall, einen doppelten Contrapunct in der Octave von sechs Tacten zu machen, ohne die Regeln davon zu wissen (German for “A method for making six bars of double counterpoint at the octave without knowing the rules”) (1758) and Maximilian Stadler’s Table pour composer des minuets et des Trios à la infinie; avec deux dez à jouer (French for “A table for composing minuets and trios to infinity, by playing with two dice”) (1780).”

As conversations continued, we brought in the composer and WebXR creator Jeff McSpadden who added new elements to the mix, like the Mayan Number System.

A lot of these ideas and techniques did not make it into the finished version but it was fun and challenging to try things out along the way. One of the things that we did get working but chose not to include, since it was too complex for the beginner, was granular synthesis. Here’s a description from Wikipedia:

“Granular synthesis is a basic sound synthesis method that operates on the microsound time scale.

It is based on the same principle as sampling. However, the samples are not played back conventionally, but are instead split into small pieces of around 1 to 50 ms. These small pieces are called grains. Multiple grains may be layered on top of each other, and may play at different speeds, phases, volume, and frequency, among other parameters.

At low speeds of playback, the result is a kind of soundscape, often described as a cloud, that is manipulatable in a manner unlike that for natural sound sampling or other synthesis techniques. At high speeds, the result is heard as a note or notes of a novel timbre. By varying the waveform, envelope, duration, spatial position, and density of the grains, many different sounds can be produced.”

Here is an early test that Glenn made to demonstrate the technique using a clip from the film Koyaanisqatsi with the fluctuations in a data set remixing the soundtrack. You can easily hear the difference in the underlying audio:

Here’s the ‘before’. This is just the regular movie as it was released –

Here’s the ‘after’. Note the data set onscreen and the graph –

A section of Koyaanisqatsi with a generative, data driven soundtrack from Glenn Marshall

The Name

TwoTone was the name of an English music genre in the 1970s. Commonwealth citizens arrived with ska and reggae music which was adopted by white working class youth and mixed together into an inclusive musical expression. From Wikipedia: “Two-tone (or 2 tone) is a genre of British music that fuses traditional ska with musical elements of punk rock.Its name comes from 2 Tone Records, a label founded by Jerry Dammers of The Specials,and references a desire to transcend and defuse racial tensions in Thatcher-era Britain”

2 Tone Records


TwoTone Team:

Hugh McGrory, CEO/Co-founder at Datavized, TwoTone Project Lead

Debra Anderson, CSO/Co-founder at Datavized, TwoTone Project Manager

Brian Chirls, CTO/Co-founder at Datavized, TwoTone Lead Technologist

Alberto Cairo, Knight Chair in Visual Journalism at the School of Communication of the University of Miami, Project Mentor

Simon Rogers, Data Editor, Google News Lab, Google News Initiative, Project Commissioner

Glenn Marshall & Jeff McSpadden, Music Advisors

TwoTone is a free and open-source data sonification tool that turns data from spreadsheets into sound and music. TwoTone is web app made by Datavized Technologies with support from Google News Initiative.

Originally published at on March 5, 2019.



Sonify innovates at the intersection of audio, data and emerging technologies. This blog is a collection of posts from company founders and our network of collaborators. Visit to learn more about us.

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Hugh McGrory

Emerging Media | Art and Technology, Co-founder at Sonify: audio, data and emerging technologies.