Capturing Every Note

An impromptu jam session might just be a musician’s breakthrough moment. But what if they didn’t record it?  

“That’s happened many times in my life,” says pianist and software engineer Charles Weinberger ’15. “I played something really well … and then I just felt this loss. I thought, ‘Oh, that was so good. I’ll never play that again. Why can’t I always be recording?’” 

So Weinberger came up with a solution: JamCorder. 

Launched in 2024, JamCorder is a device that attaches to a piano and automatically records what is played, so musicians can jam more and worry less.  

While many audio-recording devices exist, most produce audio files that can quickly become quite large. By comparison, JamCorder transcribes data on the pitch, timing and velocity of every note played, using a digital music interface called MIDI, a standard technology developed in the 1980s for connecting keyboards to computers.  

“By recording just the notes, it reduces the amount of data by about a thousand times,” he explains. Twelve hours of music take up about the same amount of data as a single smartphone photo, he adds. With 16 GB of storage, JamCorder stores up to 25,000 hours — or three years! — of data.  

“You get recording times so big that you just don’t need to think about it,” Weinberger says. “You can just leave it on your whole life.” 

Using the accompanying JamCorder app or other software programs that can read MIDI data, musicians can then review exactly what they played — and how they played it. The app also allows users to bookmark, loop, layer and group recordings to envision small samples as fuller productions. The device has caught the attention of musicians including Lionel Richie and Coldplay, who have ordered JamCorders. 

Now based in San Francisco, Weinberger majored in computer science at Northwestern and has worked as a software engineer for over a decade.  

“Northwestern was big for me” he says. “Two of my best friends from Northwestern are also entrepreneurs, so I met a lot of people with the same drive.”