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mobile phone orchestras and ensembles
In January 2008 the first repertoire-based mobile phone orchestra had its first concert at CCRMA, Stanford University. Founding directors were Ge Wang (Stanford), Henri Penttinen (HUT) and me. We had a bunch of other concerts since, in Genova, Italy, in Belfast, UK and in San Francisco. Henri has since spawned his own Mobile Phone Ensemble in Helsinki and I hope there will be many more to come! Check out the MoPho web site! Selected publications:
- Wang, G., Essl, G., Penttinen, H.
"Do Mobile Phones Dream of Elecric Orchestras?"
In Proceedings of the International Computer Music Conference (ICMC), Belfast, UK 24.-29. August, 2008.
[pdf]
expressive mobile interactions
CaMus is a software implementation that allows mobile camera phones to operate as composition and performance devices. CaMus is short for Camera Music, indicating that we use the camera as a sensor to detect motion and allow for performance. Either we use special 2-D markers or optical motion detection. Using this technology, performers can navigate a plane virtual space where sound sources can be placed and moved around. Visible parts of this virtual plane are displayed on the mobile phone's small screen and we offer various ways to help navigation. This is join work with Michael Rohs and Martin Roth. Selected publications:
- Rohs, M., Essl, G.
"CaMus2 - Optical Flow and Collaboration in Camera Phone Music Performance"
In roceedings of the Seventh International Conference on New Interfaces for Musical Expression (NIME), New York, USA, June 6-10, 2007.
[pdf]
- Rohs, M., Essl, G., Roth, M. "CaMus: Live Music Performance using Camera Phones and Visual Grid Tracking" in Proceedings of the 6th International Conference on New Instruments for Musical Expression (NIME), pp. 31-36, Paris, France, June, 2006.[pdf]
- Essl, G., Rohs, M. "ShaMus - A Sensor-Based Integrated Mobile Phone Instrument" to appear in Proceedings of the International Computer Music Conference, Copenhagen, 2007.[pdf]
structure-preserving physical modeling
We use structure-preserving ideas to model waves in the plane. We already have really very successful simulation method for the one-dimensional wave equation called digital waveguides. But can we do as well in 2-D? I explore the structure of the wave equation in the plane to figure out what the exact correspondences are between the wave equation in 1-D and 2-D and how one can find efficient methods while preserving key structures. The picture to the left shows the reduced problem of tracing wave fronts. One can show that only smooth curves and specific sharp edges called cusps can ever exists and this can be seen nicely in the rendered picture. This is of a single point excitation off center after a few reflections. Selected publications:
- Essl, G., "Computation of Wavefronts on a Disk I: Numerical Experiments," Post-conference publication, "Third Irish Conference on the Mathematical Foundations of Computer Science and Information Technology, Dublin, Ireland, July 22-23, 2004." Electronic Notes in Theoretical Computer Science 161, 25-41, 2006.[pdf]
- Essl, G., “"Whispering" waves and Bate's ridges in numerical experiments” Acoustics Research Letters Online 6:3, 227-231, 2005.[pdf]
sensory-rich interfaces
PebbleBox is one in a series of tangible interface designs that explore the role of action and physicality in expressive interfaces (the others have descriptive names like "Scrubber" or "DaGlove"). Jerome Bruner called this connection "enactive" and and psychologists today talk about sensorimotor integration. We look at the malliability of the device by manipulating synthesized sound while keeping the tactile experience the same. This is joint work with Sile O'Modhrain on the designs. Also joint with Charlotte Magnusson, Joakim Eriksson and Sile on experiments. Selected publications:
- Essl, G. , O'Modhrain, S., "An Enactive Approach to the Design of New Tangible Musical Instruments", Organised Sound 11:3 285-296, 2006.[pdf]
- Essl, G., Magnusson, C., Eriksson, J., O'Modhrain, S. "Towards evaluation of performance, control of preference in physical and virtual sensorimotor integration"
In Proceedings of ENACTIVE 2005, the 2nd International Conference on Enactive Interfaces, Genoa, Italy, November 17-18, 2005.[pdf]
abstract sound synthesis
Circle maps are the simplest non-linear extensions of linear discrete oscillators. Essentially they are just a one-parameter perturbation of the linear case. These are very simple maps that can be implemented as one-step iterations. Yet they already exhibit a wealth of the phenomenology of non-linear effects, like mode-locking, bifurcation and chaos. That actually makes them hard to control, but the plus side is that these are stable for all choices of parameters and a lot of their properties are rather well understood. We look at circle maps and other oscillators for new building blocks for abstract sound synthesis, which are both expressive and complex, yet algorithmically cheap (so that we can run them on our mobile devices without breaking a sweat). Selected publications:
- Essl, G. "Circle maps as a simple oscillators for complex behavior: II. Experiments" In Proceedings of the International Conference on Digital Audio Effects, Montreal, September 18-20, 2006.[pdf]
- Essl, G. "Circle maps as a simple oscillators for complex behavior: I. Basics"
In Proceedings of the International Computer Music Conference, New Orleans, November, 2006.[pdf]
A lot of stuff - also on other, older projects (pre-2005ish) like banded waveguides, non-propagating excitations and more - can be found in my publications! Link is on the left. If you are interested in my work on synthesizing dispersive media efficiently using banded waveguides, a bit of that is still available at the Sound Lab pages at Princeton.
Some linked papers may be copyrighted. They are provided here solely for individual, educational, academic, fair use.