It was a ton of fun to play a small role in this project lead by the brilliant Marta Ewa Lech & @jonassjuul.bsky.social. A lot of drama & change in the world of music reflected in the song-dynamics of the Billboard Hot 100!

Extra: Also, thanks to Alice Nadeau. Alice brought to my attention that some artists have recently been arguing that it is getting harder to make a hit (see e.g., www.bbc.com/news/enterta...). Our conversations sparked the idea for this project.

7/7
This was a fun project to work on and write up. Thanks to the great Marta Ewa Lech and the always-wonderful @sunelehmann.com .

6/7
Our results are especially interesting in the context of collective attention: Whereas books, news stories, movies, etc. get popular, then lose popularity at a higher and higher pace (see www.nature.com/articles/s41...), the most-popular hit songs now stay popular for longer.

4/7
On today’s chart, there are

- Fewer songs by new artists
- More songs performed by established ‘hitmakers’ (but these songs reach lower positions on average than used to be the case for hitmakers)
- Many, many more collaborations than previously.

3/7

- Song chart lifetimes peaked in the 2000s, then dropped.
- In the past two decades, lifetime inequality has surged (gini >0.6), because
- Mega hits are now staying on the chart for months, even years;
- Churn in the bottom is huge.
(tales of both the winner-takes-all and long tail theories)

2/7

The Billboard Hot 100 has tracked US music consumption since 1958.

In her master’s thesis, the awesome Marta Ewa Lech studied all chart entries to understand how song and artist success has evolved since the chart’s creation.

New paper out in EPJ Data Science!

We analyze 65 years of Billboard Hot 100 data to ask:

🎵Are songs moving differently up and down the chart nowadays?
📉 Are hits shorter-lived?
📈 Or do superstars dominate more than ever?

Paper: epjdatascience.springeropen.com/articles/10....
🧵 1/7

I am ecstatic to join the Danish Young Academy starting September 2025.

I cannot wait to meet the other members, start new collaborations, and learn more about the new opportunities and challenges that lie at the intersection of research, universities, and society in Denmark.

New paper alert. "More is different" & the LLMs.
LLMs are usually studied in isolation. But what happens when they start interacting? We explored this by looking at their collective behaviour.
Work with @ariel-flint.bsky.social and @lajello.bsky.social
1/

The new pope has a bachelor degree in mathematics! And I thought the job prospects could not get any better for math majors!

Luca Maria Aiello becomes Full Professor
nerds.itu.dk/2025/04/01/luca-m
Congratulations Luca @lajello.bsky.social, well deserved! 🎉👨‍🏫

We have several open positions, both Phd & Postdoc: nerds.itu.dk/positions/

On the topics of epidemic preparedness, and network science & AI & #ScienceOfScience #SciSci
Deadlines in April and May!

📢 Call for PhD and Postdocs: Using data science to improve epidemic preparedness
nerds.itu.dk/2025/03/25/c...

We are looking for Phds and Postdocs to join @jonassjuul.bsky.social at @itu.dk in Copenhagen improving inference, forecasting, and mitigation in future pandemics. Deadline May 1st.

3 relevant papers:
- www.nature.com/articles/s41...
- www.nature.com/articles/s41...
- journals.aps.org/pre/abstract...

I am hiring PhD students and Postdocs to join me in beautiful Copenhagen. Together, we will develop data science methods to improve epidemic preparedness.

Copenhagen is amazing, salary is good, we have plenty of funding, and a great community.

Read more..: candidate.hr-manager.net/ApplicationI...

There are days in life that shake you.

I’m shattered 💔 to share that I just found out that the US Government terminated my 2024 NIH Director’s Early Independence Award (~$2 million), threatening my long-promised assistant professor job at Columbia University
& academic career... 1/🧵

🎉 New paper in PNAS: Urban highways are barriers to social ties
https://www.pnas.org/doi/10.1073/pnas.2408937122

Highways are barriers that cut opportunities for social ties. We quantify this effect by overlaying the US highway network with millions of social ties from Twitter.

New NERDS paper on academic mentorship
nerds.itu.dk/2025/03/03/n...

Jonas wins Novo Nordisk Data Science Investigator Grant! 🥳
nerds.itu.dk/2025/02/26/j...