I thought this last challenge was going to be more fun and less challenging than it turned out to be. A quick glance at SoundBrush gives the impression that it could be quite a usable application, a more visual take on the standard step sequencer that has you drawing on the iPad screen to create music.
On further investigation, the experience of using the program is revealed to be less than ideal. For example, although the images show it is possible to create long flowing curves, in practice these just result in a series of steps instead of the sweeping glissandos they imply. A more damning problem lies in the sound production, which is highly flawed: there is no natural decay or looping to any of the four available sounds. This results in short notes sounding unnaturally truncated, while the longer notes fade out before they should, making it awkward to produce certain combinations of notes. On the positive side, four colours represent the different instruments and this makes it possible to build more complex arrangements than is possible in most standard step sequencers, though the lack of any control of dynamics and the truncated note lengths can just result in a bit of a muddle. I guess this app would be fine as a toy, but it misses the mark as even a basic musical sketchpad.
The Rührtrommel (literally ‘stirring drum’ in German) is another handmade instrument from klingklang.at, picked up at the Christmas market in Karlsplatz (as with the Walnut Flute). It consists of eight wooden keys arranged in a circle in ascending order of size, rather like a short, rolled-up xylophone. A wooden mallet is used to strike the notes, which can be done individually or in a circular, stirring motion producing a unique character of its own.
The first track has two slow layers from SoundBrush (flute and strings) playing a melody that is overlaid with a pair of tracks played xylophone-style on the the drum.
Multiple layers in SoundBrush (piano, flute and strings) meet a simple Rührtrommel accompaniment that becomes more complex towards the end of the piece.
Finally, this last SoundBrush track is based on the picture shown here (my signature in four colours), slowed down as much as possible for playback, then passed through a filter and delay (resulting in the accompanying deep bubbling effect). Two tracks of Rührtrommel are also heavily processed through different chains of distortion, filtering, pitch-shifting and delay to create the squeaking, burbling percussion.