Polygraph makes data visualization stories about music, film, and culture, often using Spotify data and hip-hop lyrics.
HN commenters link its "timeless" songs analysis on long-term popularity and its rapper vocabulary chart, which one found a source of conversation.
I actually think that "longevity" is a better term. But I only realized that after I wrote the article. Here's another version of the article that never really was released, which focused on longevity over timeless: http://poly-graph.co/timeless/nodiggity.html
We only have two data points in this work: today and release date. So longer trends like the one you pointed out might be lost in time.
Sales numbers are not that exciting when some people can look at actual streaming statistics. Something like http://poly-graph.co/timeless/ with album sales vs median track streaming count would be interesting. (median, because albums are not about hit songs)
Thanks for this: http://poly-graph.co/vocabulary.html I've gotten hours of conversation out of it.
Also so happy to see that "You Got Me" by The Roots got 6 million streams in 2014. That is the definition of a future timeless track.
It's not at all clear that popularity at time of publication correlates well with long term popularity for songs. See http://poly-graph.co/timeless/
THIS: http://poly-graph.co/timeless