  Can live music events generate complex contagion in music streaming? This
paper finds evidence in the affirmative, but only for the most popular artists.
We generate a novel dataset from Last.fm, a music tracking website, to analyse
the listenership history of 1.3 million users over a two-month time horizon. We
use daily play counts along with event attendance data to run a regression
discontinuity analysis in order to show the causal impact of concert attendance
on music listenership among attendees and their friends network. First, we show
that attending a music artist's live concert increases that artist's
listenership among the attendees of the concert by approximately 1 song per day
per attendee (p-value<0.001). Moreover, we show that this effect is contagious
and can spread to users who did not attend the event. However, the extent of
contagion depends on the type of artist. We only observe contagious increases
in listenership for well-established, popular artists (.06 more daily plays per
friend of an attendee [p<0.001]), while the effect is absent for emerging
stars. We also show that the contagion effect size increases monotonically with
the number of friends who have attended the live event.
