Heads up! After some time fiddling with LibGDX, libpd and the Intel Multi-OS-Engine, I managed to port PocketComposer from Android to iOS, reusing about 95% of the existing code.

Available for iPhone and iPad:


Of course, the Android version is also still available for tablets on phones. The app works the same on both platforms and will be kept in sync in the future as far as possible.

Please note that since one cannot directly access the internal storage on iOS, all files are kept in the app’s documents folder. To import wave files from another application, you have to connect it to your laptop and open iTunes to access the documents folder. In the future, I will try to add other ways for importing and exporting files.

If you have feedback or a question, feel free to add a comment to this post.


Good news: A workshop about Pocket Composer will be held at the 26th EAS Conference (European Association of Music in Schools) by Tamara Flad and me in Jelgava, Latvia. The conference is taking place from March 14 to 17.

To guide further improvement of the app until March, I decided to run a beta testing survey with Google forms: https://goo.gl/forms/58CuPhTuhAdFJLA63

If you would like to contribute, please download the app (if you haven’t done so already) and fill out the survey. Any feedback will be gladly accepted and added to the ever-growing development todo list.

A major update of the Pocket Composer app is available in the play store. It includes a polished UI, first use tutorials and many bugfixes. As a new feature, you can set the probability for each edge in the arrangement graph to create randomized arrangements.


The new image assets were drawn by Tamara Flad , who did also present the app to fellow students in Trossingen in several workshops. Check out this video from Regio TV: Brückenbauer zwischen Musiktradition und einer digitalisierten Welt. At the beginning of the video, you can see people playing with the app 🙂

I am also happy to announce that Pocket Composer will be the a major part of my bachelor thesis in music design. Any progress on the thesis will be posted here.

The game Heckerhut (derived form the name Friedrich Hecker and the German word for hat) was developed during the Code for Culture game jam last summer.

I am happy to announce that the jury grading the games gave a special prize to to our team: Tatyana, Fabian, Adrian and me.


You can download the game for OS X and Windows here:

Win: https://www.dropbox.com/s/xwtntfwhjnampu6/171205_Heckerhut_windows.zip?dl=

Mac: https://www.dropbox.com/s/ujo70729sw5xde1/171205_Heckerhut_mac.zip?dl=0

It was made for the House of History Baden-Württemberg in Stuttgart. The story of the game takes place in the German revolution of 1848. One of the reasons the revolution failed was because there were not enough revolutionary citizens.

In the game, you play Friedrich Hecker wearing his famous hat and throwing flyers with rebellious content at citizens to convert them to fierce revolutionaries. As soon as a citizen picks up a flyer, he will head straight to the exit of the level to start the revolution. But watch out: the police men will try to arrest Mr Hecker and his fellowship.

The overall experience of creating a game in the heat of a 36 hour jam as well as finalizing it in the months after the jam was very rewarding. Btw, the game audio is implemented in the Wwise audio engine for Unity.

As part of a study project together with a public school in Trossingen, I developed the free Android app PocketComposer. Based on earlier ideas about DAWs, workflow and inspiration and the way contemporary composers of new music like to work, the app starts with a nearly blank screen and an entry point. The design deliberately avoids a fixed grid for the rhythm (i.e., quantization), pre-recorded samples and fixed layout for your tracks.

Link to play store: https://play.google.com/store/apps/details?id=com.jf.pocketcomposer

The composer can create new audio or synthesizer items anywhere on the zoomable canvas and record sounds directly with the phone or import .wav-files from the SD card or internal memory.


The audio/synth/break snippets are connected with arrows, so a composition is essentially a directed graph. Each edge on the graph can be traversed a limited number of times. When a node has multiple children (i.e., outgoing edges), more voices are automatically added and allocated to the player. The maximum number of voices is 16.


In the following days, pupils from the Gymnasium Trossingen will work with the app. I am eager to see some bad-ass compositions with everyday sounds and a little anxious because those 8th graders might be very tough beta testers 🙂

Please be aware that the app is still in an early stage of development and is rather a proof-of-concept than a well-forged, reliable composition tool. I hope to add improvements step by step later. Bug reports below in the comments, please!

The interface was made with the 2D cross-platform game engine LibGdx

The sound engine uses libpd/Pure Data.

Between September 2015 and June 2016, I was working on my final year project for the Musikdesign studies at Trossingen. It is essentially a single player audio game where the player’s movements are tracked inside a room.

The title of the game is “Morpheus’ stairs”. Morpheus as a reference to the ancient Greek God of sleep and dreams, stairs meaning that the player has to descend several layers (this is similar to the concept of early dungeon crawler games like Rogue and Nethack).

It is easiest to describe the whole game from the player’s perspective:

“I open the door labeled Morpheus Stairs and enter a room with blind windows, no lights except for the glow of a laptop in the corner. The game developer gives me a special kind of headphones with a small printed circuit board attached. To play the game, I have to wear a sleeping mask and stand the middle of the room. After a short calibration (presumably of the head and positional tracker), the game starts.
A whispering voice explains that I have to find a specific spot in the room and that I have to listen closely and walk carefully.

After the introduction, another voice says that I have to look for the prime, probably referring to the musical interval.

A piano starts to play two notes. After a while, I notice that the interval between the notes changes when I turn around. Once I have fixed a prime, I start walking towards it.
I am afraid to hit the walls (since I am not able to see anything). However, the tracking system detects the proximity of the walls very accurately and plays a clear acoustical warning.

Inside each level, I use different systems of acoustical navigation to zero in on the entrance to the next level. The whispering voice tells me how to navigate. In the seventh level, the voice is silent. I get confused and start to walk around, looking for the exit. The sound of a beating heart starts to get long louder and louder, hammering into my ears. Walking around, I seem to be close to a wall more and more often. Are the walls closing in on me? Are these acoustical warnings reliable anymore? Is the tracking system broken?

Bravely, I walk a few steps, disregarding the yelling sound telling me that there is a wall. Suddenly, the heart beat stops. Everything I have heard before is played backwards with a very high pitch. Then… silence except for the calm waves of the sea. Game over.

To experience the game yourself, you can download a standalone version for Mac OS X. In the standalone, the tracking system is replaced by playable third person character. You can see the room, but the exits are hidden.

There is also a video of a complete walkthrough:

The tracking system transfer the positioning data wireless to an Arduino device which is connected via USB to a Macbook. The USB data is read via an emulated serial port, translated to OSC packets and forwarded to the Unity application which you can see in the video on screen. Thus the real movements in the room are directly projected into the virtual room of the game.

This final year project would not have been possible without the support from many people, who tested early versions, provided hardware and provided advice on the content and game mechanics. Thank you!

One assignment in this summer’s composition course was to use the theme from the well-known medieval hymn dies irae, slightly modify it and create different variations based on the theme.

You can find the score as a PDF here:


The theme’s cinematic feel was exploited a lot, there are many movies where you can hear citations of the theme: