About

Chris Chafe is a composer, improvisor, and cellist who develops much of his music alongside computer-based research. He is the Duca Family Professor and a member of the faculty at Stanford University's Symbolic Systems Program, where he also serves as Director of the Center for Computer Research in Music and Acoustics (CCRMA). His work involves digital synthesis, music performance, and real-time internet collaboration, with notable projects such as CCRMA's jacktrip initiative that facilitates live concerts with musicians worldwide. Chafe has pursued methods for digital synthesis and online collaboration at institutions including IRCAM in Paris and The Banff Centre in Alberta. He has also held positions as an International Visiting Research Scholar at the Peter Wall Institute for Advanced Studies at the University of British Columbia, a Visiting Professor at the Politecnico di Torino, and an Edgard-Varèse Guest Professor at the Technical University of Berlin. His compositions include gallery and museum music installations, collaborations with artists, scientists, and medical doctors, and works like the Earth Symphony, the Brain Stethoscope project, PolarTide, Tomato Quintet, and Sun Shot. Chafe's innovative approach combines music, technology, and interdisciplinary collaboration to reach audiences in novel venues and contexts.

Research topics

• Computer Science
• Artificial Intelligence
• Machine Learning
• Data science
• Mathematics education
• Engineering
• Art
• Geography
• Speech recognition
• Human–computer interaction
• Psychology

Selected publications

• A Comprehensive Evaluation of Networked Music Performance Using LEO Satellite Internet: The Starlink Use Case

  IEEE Transactions on Network and Service Management · 2025-07-15 · 1 citations

  articleSenior author

  Networked Music Performance (NMP) is one of the most challenging real-time applications in which musicians can play together using the internet without being physically together. Nowadays, the connection technology can have performance that guarantees an adequate Quality of Experience (QoE) for NMP. On the other hand, there are millions of musicians who live in remote and rural areas without access to high-speed network connections. The promising LEO satellite internet technology could fill this gap and democratize NMP in remote places. This paper aims to provide an analysis of Starlink’s capability to meet the stringent requirements of NMP. We present an analysis of network metrics that are relevant to NMP applications and assess the NMP software JackTrip in order to test a real NMP application with LEO satellite internet. The evaluation of the RTT, One-way delay, Packet loss, and jitter in different scenarios poses some challenges for the NMP scenario. We present the results of two live NMP jamming sessions with musicians, proposing an adapted QoE model that incorporates both objective and subjective metrics. With a tailored buffer strategy and the ability of a musician, we were able to obtain an adequate QoE, overcoming the challenges introduced by LEO satellite internet.

  PublisherDOI

• Global Net Equity: The Role of LEO Satellites Towards 6G Connectivity Landscape

  2025-07-07

  articleSenior author

  The evolution of Low Earth Orbit (LEO) satellite systems is poised to play a key role in shaping the concept of Global Net Equity in the 6G landscape. This paper explores the integration of LEO satellite connections within terrestrial and non-terrestrial network (TN/NTN) systems, presenting them as essential components for future global connectivity. Leveraging measurements from the commercial solution Starlink, we analyze the current performance of LEO satellites, highlighting their limitations in stability for real-time applications such as Networked Music Performance (NMP). Using JackTrip, we conducted jamming sessions to evaluate the feasibility of NMP over Starlink, highlighting key challenges related to latency and synchronization. Moreover, our data collection (publicly available) took place during a solar storm, providing a unique opportunity to observe its impact on the Starlink constellation. While significant obstacles remain, notably in achieving the stability required for latency-sensitive applications, the study underscores the promise of LEO satellites in addressing connectivity needs where terrestrial networks fall short.

  PublisherDOI

• Perceiving Slope and Acceleration: Evidence for Variable Tempo Sampling in Pitch-Based Sonification of Functions

  ArXiv.org · 2025-08-09

  preprintOpen access

  Sonification offers a non-visual way to understand data, with pitch-based encodings being the most common. Yet, how well people perceive slope and acceleration-key features of data trends-remains poorly understood. Drawing on people's natural abilities to perceive tempo, we introduce a novel sampling method for pitch-based sonification to enhance the perception of slope and acceleration in univariate functions. While traditional sonification methods often sample data at uniform x-spacing, yielding notes played at a fixed tempo with variable pitch intervals (Variable Pitch Interval), our approach samples at uniform y-spacing, producing notes with consistent pitch intervals but variable tempo (Variable Tempo). We conducted psychoacoustic experiments to understand slope and acceleration perception across three sampling methods: Variable Pitch Interval, Variable Tempo, and a Continuous (no sampling) baseline. In slope comparison tasks, Variable Tempo was more accurate than the other methods when modulated by the magnitude ratio between slopes. For acceleration perception, just-noticeable differences under Variable Tempo were over 13 times finer than with other methods. Participants also commonly reported higher confidence, lower mental effort, and a stronger preference for Variable Tempo compared to other methods. This work contributes models of slope and acceleration perception across pitch-based sonification techniques, introduces Variable Tempo as a novel and preferred sampling method, and provides promising initial evidence that leveraging timing can lead to more sensitive, accurate, and precise interpretation of derivative-based data features.

  PublisherOA PDFDOI

• Composing Resilient Software: Architectural Evolution and Collaborative Governance in JackTrip's Open-Source Journey

  HAL (Le Centre pour la Communication Scientifique Directe) · 2025-06-25

  articleOpen accessSenior author

  International audience

  PublisherOA PDF

• Distributed acoustical meshes on the Internet

  The Journal of the Acoustical Society of America · 2024-10-01

  article1st authorCorresponding

  An acoustical mesh distributed over the Internet is constructed of scattering junction nodes with bidirectional audio streaming between them. Components of common network music performance (NMP) applications like JackTrip can be adapted for experimentation with the concept. In the usual context of ensemble NMP, an audio hub server accepts bidirectional audio connections from multiple clients. The clients are located apart from each other physically and the hub server handles audio to and from the ensemble of sites, typically comprising a band or choir. The usual spoke and wheel topology (single hub server/mulitple hub clients) requires some modifications to run as a mesh of interconnected scattering juntions. The resulting waveguide mesh topology is explored for its properties, some of which resemble extensions of waveguide mesh physical model simulations of musical instruments and rooms. The acoustical medium that this creates is a live, vibrating acoustic mesh across Internet space. Unique properties, such as non-uniform distribution of nodes, are described in an experiment that explores analogies to plates and membranes and is characterized by the inherently anisotropic propagation of the network.

  PublisherDOI

• Silicon

  Open Book Publishers · 2024-04-08

  book-chapterOpen access1st authorCorresponding

  This piece reflects on the composition of the ‘Silicon’ movement.

  PublisherOA PDFDOI

• VIMEO Livestream Concert: The Telematic Circle—Celebrating Free Music performed live over the internet (https://vimeo.com/event/4551097/281fe79260)

  The Journal of the Acoustical Society of America · 2024-10-01

  article

  In the spirit of a virtual meeting, the Technical Committee Musical Acoustics hosts a telematic concert featuring freely improvised music in the classic and jazz avant-garde tradition. In 2007, we started a Telematic Circle between Rensselaer Polytechnic Institute and Stanford University, performing free music weekly between two music seminars led by Pauline Oliveros at RPI and Chris Chafe at Stanford. This project was possible through a new low-latency INET2 internet network, Chafe’s low-latency audio software, Jacktrip, and the adequacy of free music for such collaborations. Over the years, the Telematic Circle expanded to other institutions in the US and other countries. This concert will highlight a three-way connection between Rensselaer Polytechnic Institute, Stanford University, and Suny Stonybrook, featuring local musicians from all three institutions. The concert can be viewed via a VIMEO Livestream (https://vimeo.com/event/4551097/281fe79260).

  PublisherDOI

• Democratizing Networked Music Performance with a RL-Based SD-WAN

  IEEE Communications Magazine · 2024-12-01 · 8 citations

  articleSenior author

  Networked Music Performance (NMP) has increased its spread in the musician community because of its capability to connect players who are not physically together. However, NMP relies on stringent requirements, such as low latency, which can be challenging to achieve when musicians are located in different parts of the world. Despite the advancement of communication technologies, NMP guarantees a proper quality experience for only those with high-performance connections. We propose an architecture that aims to democratize NMP, extending its reach to remote areas and individuals lacking access to high-performance networks. In particular, we leverage Software Defined Wide Area Network (SD-WAN) technology, allowing the integration of a Low-Earth Orbit (LEO) tunnel in the NMP system.

  PublisherDOI

• Content Adaptive Front End For Audio Classification

  arXiv (Cornell University) · 2023-03-18

  preprintOpen accessSenior author

  We propose a learnable content adaptive front end for audio signal processing. Before the modern advent of deep learning, we used fixed representation non-learnable front-ends like spectrogram or mel-spectrogram with/without neural architectures. With convolutional architectures supporting various applications such as ASR and acoustic scene understanding, a shift to a learnable front ends occurred in which both the type of basis functions and the weight were learned from scratch and optimized for the particular task of interest. With the shift to transformer-based architectures with no convolutional blocks present, a linear layer projects small waveform patches onto a small latent dimension before feeding them to a transformer architecture. In this work, we propose a way of computing a content-adaptive learnable time-frequency representation. We pass each audio signal through a bank of convolutional filters, each giving a fixed-dimensional vector. It is akin to learning a bank of finite impulse-response filterbanks and passing the input signal through the optimum filter bank depending on the content of the input signal. A content-adaptive learnable time-frequency representation may be more broadly applicable, beyond the experiments in this paper.

  PublisherOA PDFDOI

• Playing Attention

  ECHO a journal of music thought and technology · 2023-02-17

  article1st authorCorresponding
  PublisherDOI

Frequent coauthors

• Julius O. Smith

  Stanford University

  12 shared

• Takako Fujioka

  Stanford University

  11 shared

• Romain Michon

  9 shared

• Prateek Verma

  Datta Meghe Institute of Medical Sciences

  9 shared

• Auriel Washburn

  University of California, San Diego

  8 shared

• Matthew J. Wright

  7 shared

• John Granzow

  University of Michigan–Ann Arbor

  7 shared

• Cristina Rottondi

  Polytechnic University of Turin

  7 shared

Awards & honors

• Center for Digital Health Award, Stanford University (2023)
• High-Impact Technology Grant, Stanford University (2023)
• Coastal Futures Ecoacoustic Music Prize, Coastal Futures Con…
• Edgard Varèse Guest Professorship, Technical University of B…
• International Visiting Research Scholar, Peter Wall Institut…