Composing Microbial Bebop with Peter Larsen

October 2012

Ever heard Blues for Elle, Bloom, or 50ºNorth/4ºWest, the sonification of seasonal variation patterns in microbial communities? These fast spreading, going-viral Microbial Bebop tunes were obtained by Biologist Peter Larsen of the Department of Energy's Argonne National Lab as he mapped results from data mining efforts regarding blue-green algae in the western English Channel to virtual musical scores.  You can listen to these  Sea Songs on www.livescience.com.

"Microbial ecology data is comprised of many separate observations," Larsen emailed when queried. "Each observation is made up of potentially thousands to tens-of-thousands of individual measurements of microbial species abundance and environmental parameter data.” For example, Blues for Elle captures seasonal photosynthesis change based on parameters as numerous as temperature, phosphate, nitrate, nitrite, salinity, silicate, and chlorophyll. Bloom sonifies chlorophyll vs. salinity based on the occasional abundance of Cyanobacteria, Vibrionales, Opituates, Pseudomonadales, Rhizobiales, Bacillales, Oceanospirillales, and Sphingomonadales. 50ºNorth/4ºWest sonifies chlorophyll vs. temperature based on new data for Rickettsiales, Rhodobacteriales, Flavobacteriales, Cyanobacteria, and Pseudomondales as well as data previously used to compose Blues For Elle.

The beauty of the dynamics of microbial communities tends to be readily apparent for the mathematician and revealing it to the nonscientist is part of the appeal of sonifying. However, sonifying is not motivated by mass appeal. “The goal of Microbial Bebop is to select a subset of measurements from data and highlight the relationships between measurements,” Larsen writes. The musical counterpoint is indeed useful in highlighting connections between model parameters and, more generally, in making sense of large sets of data that are not easy to graph. "Biological systems are very rich," comments WUSTL Professor of Mathematics Ed Spitznagel "and music is also very rich." One advantage of a musical representation, for example, is that it allows for a result that would appear jumbled in a two dimensional representation to be clearly heard as a chord.

While the manuscript for Microbial Bebop is still under review, when asked about the process of converting data to music, Peter Larsen kindly summarized his general approach:
1) Each observation in a dataset is one measure of music. Each measure is made up of a melody and chords.
2) Data is normalized to integer values. Each integer value is mapped to a specific note or chord.
3) Notes are used to derive melody. Notes for the melody in each measure are rectified to harmonize with chords.
Additional biological data can be translated and incorporated by changing patterns of note duration, by changes in chord patterns, or by changes in the percussion style.
For inspiration, Larsen and his team used the Jazz educational software Impro-Visor to generate sound files such as those posted on www.livescience.com.

Sonification is one tool used in the modeling of biological systems. If you have an interest in this field, be sure to attend the October 22, 2012 Math Club meeting and WUSTL Professor of Biology Anton Weisstein's talk on The Beauty of Untidiness: an Overview of Mathematical Biology.  Professor Weisstein will focus on five specific areas of collaboration between mathematicians and biologists and some of the associated developing technologies and mathematical analysis.  You can read the abstract for the lecture here»

Sonification can be called upon to clarify various complex systems.  Entities such as the Sonification Lab at Georgia Tech receive many requests to convert scientific data into sound. For instance, NASA's Kepler telescope data was converted into reggae songs and the Large Hadron Collider particle accelerator provided data to create a piece on the Higgs boson particle.  To learn more, visit the Georgia Tech Sonification Lab page»  You may also visit Systems Biologist Peter Larsen at the Argonne National Laboratory»  You can download Impro-Visor, the Jazz Improvisation Advisor for the Improviser created by Professors Robert Keller and Belinda Thom of Harvey Mudd College at http://www.cs.hmc.edu/~keller/jazz/improvisor/ page»

—Math news, stories, videos, and interviews by Marie Taris, http://www.math.wustl.edu/marietaris/math.html»
(pub. 10.05, 2012)

Enjoyed this story? See also May 2012 News story  Modeling for peace with Peter Turchin»