Interview with Marc Gelfo, founder and CEO of Modacity practice app

Marc Gelfo is one of the most fascinating people I know.

He’s a fantastic horn player who has enjoyed an impressive career playing all over the world with such groups as the San Francisco Symphony, Philadelphia Orchestra, and the Hong Kong Philharmonic; he holds degrees in Cognitive Science and Computer Science, practices and teaches holistic wellness, studies spirituality and ancient wisdom traditions, and now runs a tech company centered around his musicians’ practice app — Modacity.

I’ve been looking forward to interviewing Marc for quite some time. Please enjoy and feel free to leave questions or comments below or in the official Audition Playbook discussion group.

To begin, can you give us a little background on yourself? What’s your story?

This incarnation started in Buffalo, New York and my mother named me after Marc Chagall. I was a “high creativity” youngster who loved playing piano, frolicking in nature, and learning. 

Beethoven’s music was a huge influence and companion in my pre-teen years. I started coding at age 8, picked up the horn at age 12, and started a lifelong pattern of moving between music, tech, learning, etc.  

I was rejected by 5 music schools at age 18, which stung quite a bit, so I got Cognitive Science & Computer Science degrees from Northwestern, which was one of the schools that wouldn’t let me in for music but offered me a big science scholarship.  

Marc Chagall, 1912,  The Fiddler , an inspiration for the musical   Fiddler on the Roof

Marc Chagall, 1912, The Fiddler, an inspiration for the musical Fiddler on the Roof

I applied science to French horn, was able to practice differently and achieve an international symphony career that included six seasons with Hong Kong Philharmonic and playing on a Grammy Winning recording with San Francisco Symphony. 

Along the way I was influenced by Wing Chung Kung Fu, indigenous shamanic practices, and a constant thirst for optimization. Right now my life is guided by 4 core values: love, creativity, vitality, and prosperity.  I pivoted from full-time orchestral player to tech entrepreneur and world musician in order to more fully live my core values, and to be in a position where I can potentially help millions of others flourish in a similar way.

Which love came first in your life — music, science, tech, language, or something else?

Music popped up pretty early in my life, with piano at age 5. But my dad was an early tech adopter and had me on the computer around that age too. It’s hard to say. I don’t think my true love is a particular domain, my true love from the start has just been the human experience of play, creativity, awesomeness, discovery, etc.

At face value, some people could find these things to be quite unrelated. Do you think the opposite is actually true? How so?

As a Taoist non-dualist, the opposite of a statement is always just as true as the original statement :) Neuroscience shows that the language centers of the brain actually are built on top of musical centers. Technology is just the application of science. Science is about curiosity, discovery, discipline, even creativity. So is music. You can think of these elements like the notes of a chord. We all have our own chord. That music, science, tech, etc. come into being as a chord, inherently makes them related for me. For others, maybe less so.

How important is it for young musicians today to wear many hats — to learn more skills and cultivate more passions outside of music? Is this a necessity borne out of the state of professional “classical" music or something else? Personally — and I think this is the case with you as well — my desire to wear multiple hats is borne out of an addiction to learning and discovery and a need to experience and do more than just play the horn, but I know not everyone is this way.

With AI, blockchain, globalization, virtual reality, and ubiquitous internet just around the corner, we’re entering into a new era of economic choice and possibility. 

The traditional 20th century conservatory model of professional preparation is way outdated. Anybody who tries to “just get an orchestra job”  is probably on a less satisfying ride than an alert, curious, and flexible learner who blends their commitment to music with an embracing of the modern economic reality. 

The traditional 20th century conservatory model of professional preparation is way outdated. Anybody who tries to “just get an orchestra job”  is probably on a less satisfying ride than an alert, curious, and flexible learner who blends their commitment to music with an embracing of the modern economic reality. 

Learning and discovery are great, but it’s also about impact and actualization. According to authors like Joanna Macy of Active Hope, we are on the crux of a great turning towards a healthier and more sustainable world. This calls for everybody to do their part in creating positive impact and actualizing their best selves.  

The way I treated myself when preparing for orchestra auditions in my 20s, being self-critical, over-practicing, and being driven by fear, eventually broke me and awoke me to the importance of a musician’s holistic cultivation.

What is Modacity?

Modacity’s mobile practice app helps any goal-oriented musician — any instrument or genre — to practice more effectively with a smart organizational system, guided deliberate practice, and a suite of recording & insight tools.

What is deliberate practice? How does someone practice deliberately? And what are the benefits of doing so?

Deliberate practice is like the scientific method for creating improvement. It’s the foundation of the popular “10,000 hour rule,” which is an oversimplification but based on some solid research.

Imagine you want to fix your articulation. You’ve got a little hitch starting notes. You could just practice a bunch until it feels good and hope it sticks. You could cling to strategies like “just think about the air” which you think work, but may or may not actually work. 

Or you could actually sit down and methodically try strategies, recording yourself to separate performance from analysis, and when you’ve scientifically proven that a strategy works, focus on it and keep practicing until it becomes automatic. 

That’s how Modacity’s deliberate practice works.

Walk us through how someone might practice with Modacity.

You’re on the practicing screen for your current item, e.g. “Ein Heldenleben” or “Five octave chromatic scales” (that’s a thing, I added another octave to my horn range thanks to Modacity).

You perform your item, you listen back, you press the “Improve” button and select what you want to focus on. We supply a few options like “Articulation” or “Intonation” but you could also enter “Ease in the hand.”

Then you choose a strategy you think will make an improvement like “Keep pinky finger relaxed”. You record yourself trying the strategy, listen back, and decide if it works. If it doesn’t, try another strategy. If it does, you will be reminded to practice that strategy next time you’re on the piece. It will also be saved with “Ease in the hand” so that if you are solving that problem elsewhere, the working strategy list is there.

Finally, this activity gets automatically logged to your practice history, so you can see the improvements you made and what strategy created that improvement.

Where did the idea for Modacity come from?

It started in 2004 when I began a second undergrad in horn performance at Indiana. I had a practice journal - maybe for the first time ever - and was annoyed by how inefficient a written notebook was. All my tools were in different places, recording was not streamlined, etc. It was hard to move forward at the speed I knew was possible from my cognitive science studies.

Later on I learned about flow states (500% deeper learning) and realized that my practice environment broke flow for me. I learned more about deliberate practice, read The Talent Code, and realized that there was a huge opportunity to use software to optimize music practice. We’re talking 1,000% faster learning, to the extent that you can quantify learning.

I am also curious from the tech and business sides of this what your journey from idea to implementation has looked like. Could you talk a little about that?

This is a long story, but the short of it is:

Late 2016 - touring Asia with San Francisco Symphony, went to Virtual Reality arcade in Shanghai, realized the future has arrived.

Early 2017 - did Vipassana 10 day silent retreat, decided to follow my long dream of making practice software.

Mid 2017 - took time off (turned down many gigs, that sucked), built two apps, had more apps than users.

Late 2017 - joined Founder Institute, got my shit together, interviewed musicians, talked to investors, got a team together, founded a corporation, brought an alpha to market with 50 users.

Early 2018 - raised a little friends & family money to hire a proper engineer, launched beta of Modacity

August 2018 - launched subscriptions in Modacity, surprisingly successful. Knowing that people were willing to pay for the product was a huge relief and accomplishment.

Since that moment we’ve just been trying to improve the product and reach more musicians, a lot of folks don’t quite get the UI yet and we have a long way to go to reach my vision of 1,000% faster learning, so now it’s a balance of business viability and passion for innovation.

Who else is on the Modacity team and how did you connect?

Even before I joined my accelerator, I realized how critical team was and that I was held back by trying to do everything myself. During Founder Institute we had several weeks of assignments that involved recruiting a board of advisors, legal counsel, and first teammates. The assignments forced me to think about what my weak points were and what the Modacity endeavor needed most. I designed role descriptions around that and even wrote “Law of Attraction” style affirmations thanking the universe for delivering these wonderful folks into my life before I had met them.

I met my cofounder, Andrea, on AngelList jobs. She did a test project and I loved collaborating with her. She ended up joining as cofounder and doing all the initial branding and design work for the app, which is beautiful.  The beauty of filling roles in a company versus filling chairs in a symphony is that the runner-up can also join, and the “runner-up” for Andrea’s position also joined in a separate role, where she did more user-facing work, research, and customer support after we launched.

Our developer, Ben, found us on AngelList and he also did a test project and blew us away with his speed so we hired him to build the beta (I built the alpha myself). 

Once we had a user base, I actually recruited the next two teammates from Modacity users. Jared, our current customer service rep, was an early adopter and shared lots of values with us.

I love how much you focus on holistic wellness and spirituality in your own life and in working with others. Were you always this way or did certain experiences or circumstances lead you to discover these areas? For a long time, I separated and compartmentalized the horn and music from everything else. It took me longer than I’d care to admit to really see everything holistically and inter-connectedly and to understand, practice, and eventually embrace things like meditation, Alexander Technique, yoga, and even psychotherapy and performance psychology. For years, I just saw these as tools to throw at my problems in a panic when things in the body, mind, or on the horn broke — bandaids for broken bones — rather than the calcium that is strengthening the bone from the beginning. How did you arrive at a place where you valued and embraced these things so much?

I love the metaphor of bandaids versus calcium!

When I was a teenager I was a very black-and-white, logical thinker who identified as an atheist. There was so much unconscious suffering, so much skepticism, fear, and disembodiment, that I didn’t even have a solid vantage point from which to observe it.

The saying goes, “You don’t know what you don’t know”, and it still applies, but I believe there is a kind of “critical mass” that happens once one awakes to the interconnectedness of phenomena. There are many ways for this to happen.

In my case, I was raging against my early musical failures, and it eventually took me to a breaking point. In 2012, I was recklessly preparing for an L.A. Philharmonic audition and ended up injuring my arms, my face, and a number of my relationships! After I made it to runner-up in the audition, I flew back to Hong Kong and was hospitalized for a week.  I should have been exuberant about making runner-up, but I was devastated.  

That was the beginning of a great turning. I knew that music had to be restored to a sacred and life-affirming practice for me, and I knew there was a long road ahead to turn things around. Around that time I started “Practice Living Music,” a movement for holistic practice.

Going from massage therapists to psychotherapists to acupuncturists to shamanic healers and beyond, undoing the damage I had done to myself, I started to see that internal state is the fundamental ground from which experience unfolds. All wisdom traditions teach that change starts from within, with choice.

That was the beginning of a great turning. I knew that music had to be restored to a sacred and life-affirming practice for me, and I knew there was a long road ahead to turn things around.

How has your experiences with holistic wellness and spirituality influenced the development of Modacity, if at all?

“Blah blah blah, change starts from within”… but how do we choose to change?

Practice is the answer.

And I don’t know about you, but I want my practice to be efficient. I want my change to be effective. I want to close the gap between what science knows about learning, and what I do to master the skills that are most meaningful to my life!

So yes, underlying Modacity is the intention to share the practice of practice with everyone. There’s a lot of press these days about addictive software: Facebook dopamine addicts, Youtube’s algorithm that only cares about getting you to see more ads, etc.

There’s a part of me that wants to build software that addicts people to personal growth by making it hyper effective and radically authentic to the user’s most deeply held goals. What if people were addicted to the freedom and empowerment that comes from the path of mastery? 

Those are hypothetical of course :) More realistically, I just try to do what I can to put little tidbits in Modacity like “Stretch, Reflect, Tidy Up” as a default practice item or “Visualize Desired Outcome” as an improvement tip. 

The other piece of “developing Modacity” is my work ethic and company culture.  Starting a company wasn’t easy for me, and I sacrificed my wellness in many ways. I’m beginning to course correct now, and not surprisingly, the app and the business do better and better as I get healthier and happier. 

What is next for Modacity and for you? 

Modacity is about to launch a feature called Frameworks that allows educators, influencers, and everyday enthusiasts to create curated practice routines and share them with a simple link.

Personally, at the time of writing I’ve got about 29 hours until I head to Burning Man and completely challenge my identity, beliefs, and values, so I won’t make any firm announcements yet!


To download Modacity and find out more,



Marc Gelfo has been combining music and technology since he was 5 years old. After cognitive science & computer science degrees at Northwestern University, Marc studied French horn performance and audio engineering at Indiana University. Within two years of applying science to horn, he became an internationally touring symphony musician. His experience includes teaching and performing with thousands of musicians around the world, including San Francisco Symphony and Philadelphia Orchestra. 

Marc is Founder & CEO of Modacity, building a mobile “deliberate practice” app that helps musicians practice better and learn faster.  He loves cats, tacos, double rainbows, consciousness hacking, and phenomenally recondite semantics.


What is the
Audition Playbook? 

Click here to read more! 

Join the discussion!

Click here to join the Audition Playbook Discussion Group