Nav: Home

Quantum physics offers insight into music expressivity

March 14, 2017

Scientists at Queen Mary University of London (QMUL) are bringing us closer to understanding the musical experience through a novel approach to analysing a common musical effect known as vibrato.

Vibrato is the up-down oscillation in pitch introduced during instrumental or vocal performance, intended to add expressivity and to facilitate sound projection, and commonly used in opera. A well-timed and beautifully executed vibrato can greatly enhance the sound quality of a note, and induce strong emotional responses in the listener.

The new approach to vibrato analysis, published in the Journal of Mathematics and Music, describes for the first time the use of the Filter Diagonalisation Method (FDM) in music signal processing. The technique has origins in quantum physics and is employed to study molecular dynamics and nuclear magnetic resonance.

"We are now one step closer to understanding the mechanics of music communication, the nuances that performers introduce to the music, and the logic behind them," said project supervisor and co-author Professor Elaine Chew from the Centre for Digital Music at QMUL's School of Electronic Engineering and Computer Science (EECS).

The technique's ability to detect and estimate characteristics from very fine slivers of information comes in particularly handy in vibrato analysis and allows researchers to analyse music signals with greater precision than before.

Vibratos typically oscillate at a rate of 4-8 cycles per second, or with a period of 125-250 milliseconds per cycle. The degree to which the pitch is bent up or down can be up to half a semitone. Because vibratos happen so quickly, standard techniques which require a comparatively large window for analysing the music signal have so far struggled to accurately capture their characteristics.

"The FDM algorithm was initially developed to efficiently and effectively explore the complicated quantum dynamical resonances of atoms and molecules. Although musical signals are very different from their quantum counterparts, mathematically they share many similarities, including the characteristics of their resonances," said Dr Khalid Rajab, project co-supervisor and co-author from QMUL's School of Electronic Engineering and Computer Science (EECS).

"In fact, we found that, because they oscillate with time, the harmonics in musical signals can be more complicated to analyse than their quantum counterparts," he added. The research emerged from a project to model the differences between playing on violin and erhu, a two-stringed Chinese fiddle.

Professor Chew said: "When music for a folk instrument like the erhu is performed on a violin, it lacks the stylistic and expressive qualities of the original. One of the major sources of these differences lies in the way in which notes are elaborated (with vibrato) and the way in which the instrumentalists make their transitions between notes (using portamentos). We were interested in creating computing tools that can help reveal these differences."

The research forms part of the PhD project of Luwei Yang, first author and a China Scholarship Council doctoral candidate and Research Assistant in EECS.

Yang, an avid erhu player said: "In erhu, as in violin playing, vibrato is frequently employed to mimic the liveliness and colourful expressivity of the human voice. Contemporary erhu vibrato styles were deeply influenced by violin techniques, so it is fascinating to dig deeper into characterising the differences between them."

The researchers hope the new technique will help musicians and music teachers in their quest to achieve the perfect vibrato, assist sound artists in creating more natural sounding vibrato effects in audio production, and enable researchers to map stylistic trends in vibrato use across cultures and time.
-end-


Queen Mary University of London

Related Quantum Physics Articles:

Quantum physics: On the way to quantum networks
Physicists at Ludwig-Maximilians-Universitaet (LMU) in Munich, together with colleagues at Saarland University, have successfully demonstrated the transport of an entangled state between an atom and a photon via an optic fiber over a distance of up to 20 km -- thus setting a new record.
Quantum physics: Controlled experiment observes self-organized criticality
Researchers from Cologne, Heidelberg, Strasbourg and California have observed important characteristics of complex systems in a lab experiment.
A platform for stable quantum computing, a playground for exotic physics
Harvard University researchers have demonstrated the first material that can have both strongly correlated electron interactions and topological properties, which not only paves the way for more stable quantum computing but also an entirely new platform to explore the wild world of exotic physics.
A new quantum data classification protocol brings us nearer to a future 'quantum internet'
A new protocol created by researchers at the Universitat Autònoma de Barcelona sorts and classifies quantum data by the state in which they were prepared, with more efficiency than the equivalent classical algorithm.
Quantum physics: Ménage à trois photon-style
When two photons become entangled, the quantum state of the first will correlate perfectly with the quantum state of the second.
Quantum physics -- Simulating fundamental interactions with ultracold atoms
An international team of physicists succeeded in precisely engineering key ingredients to simulate a specific lattice gauge theory using ultracold atoms in optical lattices.
A key piece to understanding how quantum gravity affects low-energy physics
In a new study, led by researchers from SISSA (Scuola Internazionale Superiore di Studi Avanzati), the Complutense University of Madrid and the University of Waterloo, a solid theoretical framework is provided to discuss modifications to the Unruh effect caused by the microstructure of space-time.
Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.
Quantum physics and origami for the ultimate get-well card
The bizarre optical properties of tiny metal particles -- smaller than light waves -- can be captured on paper to detect even a single target molecule in a test sample.
Can artificial intelligence solve the mysteries of quantum physics?
A new study published in Physical Review Letters by Prof.
More Quantum Physics News and Quantum Physics Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.