Adrian Holovaty

Hi there! I’m a web developer and musician from Chicago, living in Amsterdam.

Blog posts

Sept. 12, 2023 — Announcing my first proper album

Dec. 1, 2022 — Adventures in generating music via ChatGPT text prompts

Nov. 11, 2022 — Thoughts on my first machine learning project

Archive | Greatest hits | RSS

My day job: Soundslice

I founded Soundslice, quite possibly the best tool for learning a piece of music! Check out my channel to get a sense of it.

I’ve given a few presentations about it, including an origin story at the XOXO Festival and this behind-the-scenes tech talk.

It has a lot of cool technical stuff I’m proud of, such as music rendering that automatically fits your device, a full-featured web-based sheet music editor and an “optical music recognition” system that can figure out the notes from a photograph or PDF. And there’s more to come — it’ll never be finished. :-)

Melodic Guitar Music

Album cover In September 2023, I released my first proper album: Melodic Guitar Music. Give it a listen.

Recommended if you like melodies, or guitars, or music.

W3C Music Notation Community Group

I’m one of three co-chairs of the W3C Music Notation Community Group, which develops and maintains specifications for notated music.

My focus is MNX, which we hope will be the next generation format for encoding music notation digitally.

Music performance

I’m a guitarist who plays fingerstyle and gypsy-jazz music. I’ve been posting YouTube videos since 2007.

The videos are categorized for you here: multitracks, fingerstyle, Beatles, gypsy jazz.

The YouTube homepage once featured my acoustic cover of the MacGyver theme. Never did figure out why. My Mario 2 gypsy-jazz video has also made the rounds.

I’ve gotten to play with some fantastic musicians over the years, and some of the highlights are in Adrian plays with other people.

Occasionally I play live throughout Amsterdam. Here’s a nicely produced video of the band.

Music teaching

Back when I lived in Chicago, I taught a few weekly gypsy-jazz classes at the Old Town School Of Folk Music.

I’ve been on the faculty at the Django in June instructional camp seven times. (And last I checked, there’s a big photo of my back on the homepage.) I highly recommend this event if you’re interested in learning Django Reinhardt-style music.

Guitarists, I have tabs for you! And I’ve put together a nice course on gypsy-jazz guitar chords.

I also have a Soundslice channel, where I post lots of little musical ideas and lick transcriptions.

Django web framework

Many years ago I co-created the open-source Django web framework, which is used by tens of thousands of people around the world! I served as co-Benevolent Dictator For Life until retiring from the project in early 2014.

I co-wrote two editions of a now-outdated book about web development with Django, published by Apress and available for free online.

Web development

I think the web is one of mankind’s all-time greatest inventions, and I love advocating for it (and experimenting with new ideas).

I’ve been building websites since 1998, and the magic feeling of “wow, I can put this code on a server and anybody worldwide can instantly access it?!” has yet to subside.

Way back in 2005, I made the site (site no longer exists), which was one of the first websites to embed Google Maps — before that was even allowed. It played a small part in influencing Google to release a mapping API. The New York Times named it one of the year’s best ideas, and evidently a screenshot of the website appeared at MoMA.

Way back in 2004, I made a browser extension that made a single website work better — which inspired the creation of Greasemonkey and “user scripts,” the idea that people can have the ability to customize websites for personal use.

These days I devote all of my programming effort to Soundslice, but occasionally I pop up to rant about the silly state of modern web development, like here: A Framework Author's Case Against Frameworks.


I founded EveryBlock, a neighborhood news and discussion site, in 2007.

We sold it to in 2009. I worked there until mid-2012, and the site eventually got shut down by its new owners, brought back, then shut down again. :-/

Here’s a retrospective I wrote, with some context on what it did.


I have a degree in journalism and have worked at a number of Internet news companies. Before starting EveryBlock, I worked at, and

During that time, I made a name for myself as somebody who did “journalism via computer programming” — which was then a new concept. I wrote a lot about this and traveled the world giving talks about how news companies should employ programmers and use their data more effectively.

An essay of mine from 2006 inspired the awesome, Pulitzer-Prize-winning site Politifact and apparently is now required reading at j-schools. Hi, students!

Alas, I’m no longer professionally involved in journalism, though I’m a proud subscriber to the Washington Post website — and think you should subscribe too.

Around the web

My Mastodon account is mostly stuff about web development.

My LinkedIn profile has the professional history.

My GitHub profile has some stuff.

My Soundslice channel has music I’ve transcribed.

Contact me

To get in touch, email adrian [at]