by Michelle Lum

Robert “Bob” Keller, a longtime Professor of Computer Science at Harvey Mudd College, passed away on Sept. 13, after a battle with brain cancer. His family was by his side.

Born in 1944 in St. Louis, Missouri, Prof. Keller studied Electrical Engineering at Washington University in St. Louis, before obtaining his PhD in Electrical Engineering and Computer Science from the University of California at Berkeley in 1970. Throughout his career in academia, Prof. Keller taught at Princeton University, the University of Utah, and the University of California at Davis, before coming to Mudd in 1991.

Prof. Keller joined Mudd as the first chair of the Computer Science Department, and taught computer science and jazz at Mudd for nearly 30 years.

He also spent time working for Stanford University, Lawrence Livermore National Laboratory, the University of California at San Diego, NASA’s Jet Propulsion Laboratory, Quintus Computer Systems, and the Aerospace Corporation.

During his time at Mudd, Prof. Keller taught courses such as Principles and Practice of Computer Science, Computability and Logic, and Computational Creativity. He was interested in neural networks, genetic programming, and parallel computing.

Prof. Keller also coached Mudd’s team in the Association for Computing Machinery International Programming contest for many years, guiding Mudd to a 1997 world finals win.

Students and colleagues remember Prof. Keller as a quiet man who was extremely well-read and knowledgeable, and had an office that doubled as a library.

“Prof. Keller’s office was so filled with textbooks that they were almost flying off the shelves,” said Brian Bentow ‘05. “He read so many books and knew about so many different technologies and languages.”

Prof. Keller loved teaching and was always willing to help. His dedication to his students manifested itself in his readiness to respond to questions at any hour of the day.

“You would send Professor Keller an email at two in the morning, and you would get a response back. I would send him an email thinking he’d get to it in the morning, so I’d plan to go to sleep,” said Bentow. “And then 10 minutes later, before I even went to bed, he would give me a response, and I would continue working.”

Prof. Keller’s quick late-night responses left a great impression on many former students.

“Professor Keller was a wonderful man who got me and my career started in deep learning. My favorite memory was from CS 42, when Prof. Keller responded a few minutes later to a question at 2 in the morning to help me with an assignment,” said Avi Thaker ‘16. “The thing I loved about him was he would always respond, and he would give unique, beautiful insights into solving problems, and he’d do it at the craziest hours. That was just amazing. He taught me what it meant to work hard.”

Prof. Keller showed me that CS is varied.

Avi Thaker ’16

A detail-oriented teacher who always had lots of lecture slides prepared, Prof. Keller also encouraged students to research and explore their own interests through open-ended projects for his courses.

“Instead of giving us a final exam in CS 42, Prof. Keller said we could do an example on multilayer perceptrons. So, I was like, ‘Okay, I’ll do that. I don’t want to take the final.’ That got me started in deep learning,” said Thaker. “Prof. Keller showed me that CS is varied.”

Prof. Keller served as a mentor to many Mudders. He taught students to develop research skills by reading papers, replicating others’ work, and then taking that to the next level. He also encouraged students to delve into areas that had been overlooked, such as neural nets in the early 2000s.

He put faith in me and lent me a hand, and that was instrumental to my career.

Brian Bentow ’05

“He was a researcher. He was an innovator. And that’s what he wanted us to become,” said Bentow. “Prof. Keller gave me the opportunity to do research with him the summer after my freshman year.  He put faith in me and lent me a hand, and that was instrumental to my career. My Harvey Mudd experience had a lot to do with Professor Keller. After college, we would talk about our families and work. We were on the same wavelength and simpatico.”

Though Prof. Keller took great pride in his work, students remember that he would make jokes from time to time, poking fun at different technologies.

A lifelong jazz enthusiast, Prof. Keller also enjoyed playing the trumpet and the piano. His tremendous passion for both computer science and jazz was an inspiration to many.

Prof. Keller often combined these two interests in his work. For example, he spearheaded the creation of the Impro-Visor music notation software, with the goal of helping jazz musicians improvise through the generation of chord progressions, color coding of notes, and other features. Prof. Keller’s research groups often worked on the project, which has been used by more than 8,000 people around the world.

At Mudd, he also taught Jazz Improvisation, a class that many former students fondly remember.

“It was inspiring to have a professor that was so passionate about something they did outside of their time at Mudd. For Prof Keller that was jazz, and I loved that he incorporated his endearment to it in his formal research,” said Akshay Trikha ‘21. “I’m grateful that I got to perform alongside him in his Jazz Improvisation class and will forever remember the encouraging looks he would give to me as I fumbled my solos.”

It was inspiring to have a professor that was so passionate about something they did outside of their time at Mudd.

Akshay Trikha ’21

Prof. Keller is survived by his wife Noel, sons Franz and Patrick, sister Irma Ward, brother Dennis Keller, and several nieces and nephews.

Contributions in Prof. Keller’s honor can be made to the Jazz Education Network’s Scholarship Program, the American Brain Tumor Association, and the Sierra Club Foundation.

Here’s what members of the Mudd community had to say about Prof. Keller:

“Professor Keller was an incredibly intellectually curious person who had broad interests in computer science and was also an avid and accomplished musician and voracious reader on many topics. His office was a small library that had floor-to-ceiling bookshelves on all of the walls with even more books stacked on his desk and other surfaces. His appetite for knowledge was inspiring and his deep care for his students and colleagues made the College a better place.” Ran Libeskind-Hadas, Professor of Computer Science

“I’m glad to have had 21 years to work with Bob. My favorite Keller-ism from that span is one I overheard as he was wrapping up a practice-presentation with a clinic team, in which I’m guessing there’d been gesture-toward-preparation, but less in the way of purposeful investment:  ‘Our goal here is not to _seem_ excellent. Our goal is to _be_ excellent.’ Classic Bob!” Zach Dodds, Professor of Computer Science

“I met Bob Keller through a talented student who was taking one of my Humanities classes back in the 1990s, Jeff Polakow. Jeff was equally enamored of computer science and Jazz, so he had something in common with Bob. Whenever I might run into Bob at a faculty meeting or at the cafeteria, we would exchange comments about our common students. In a sense, we shared educational goals: that students should be passionate about forging connections between the scientific fields of their choice and the humanities. Today, when I talk with my students about Bob, they are most in awe of his musicianship and enthusiasm for the fabulous jamming sessions he organized, so greatly enjoyed by all. Bob knew how to strike the right notes — and never failed to keep the beat.” Isabel Balseiro, Professor of Comparative Literature

“I know Prof Keller meant a lot to a lot of people over a lot of years. I got to Mudd 12 years ago and he was already an institution there. I didn’t know him well, but I think the thing that struck me the most was that he was someone who got to spend every day of his life doing exactly what he loved, combining his love of music, computer science, and teaching and interacting with the younger generations.” Matthew Richman ‘12

“I am very sorry to hear of [Prof. Keller’s passing]. Prof. Keller taught me in CS60 in Fall 2010. I was an unremarkable, stubborn, difficult student, but in class and outside it, he was kind and patient with me, which I remember even 10 years later. (Some truth in that Maya Angelou quote…) I wish his family the best.” Robert Kealhofer ‘13

“[Prof. Keller] was a measured and careful mentor during my computer science clinic project, and so obviously passionate about jazz and computation that he always made me think hard about what he had to say. I was especially grateful for the enthusiasm and welcoming attitude that he brought to his jazz improv course, which I took several times. He and I played a Billy Strayhorn duet together at one of the concert performances for that class.” Rupert Deese ‘15

“When I was a prefrosh, I saw that there was a jazz improvisation class. I played tenor sax in jazz groups at the time and decided to reach out to the professor who ran that class, Prof. Keller. Not only did he respond, he suggested I bring my sax with me on my visit and jam with the class! It was a very cool and welcoming moment for me to be able to play with all these college kids, and that experience definitely played a part in me committing to Mudd. I got to jam with him a few other times (including the brunch right before my graduation, and LTG), it was always a blast.” Sam K Miller ‘17

“I will always remember the time Prof. Keller and Noel came bowling with W-ACM members during my sophomore year. He was always the life of the party.” Jane Wu ‘18

“Coming into Mudd, I wasn’t sure if I had made the right choice in studying CS instead of music– back then it seemed like a mistake to come to a STEM school when I was so passionate about the arts. A few weeks into the semester I heard about a jazz improvisation course, so I went to go talk to the professor about signing up late. To my surprise, it was Prof Keller, my CS professor. I remember being in his office and noticing that the room was practically surrounded by books on all things CS, but at the same time there was a digital keyboard on one side of his desk and a trumpet sitting on a nearby table. For me, personally, that was one of the reasons why I liked being around Prof Keller so much; he proved to me that you could pursue and excel at all the things you’re passionate about. The other thing about Prof Keller was that he had this incredible patience when it came to teaching. During class or in office hours, he never made any question feel trivial. He would always give you his full attention, whether you [were] asking him to repeat something about finite state machines or to explain the voicings he used for a certain chord change. That’s what gave me the impression that he really cared about education, and about educating the next generation of computer scientists and musicians.” Marcos Acosta ‘23