Conversation so far:
how long have panic at the disco been together
Panic! at the Disco has been active for 16 years.
who are the members of Panic! at the Disco
Since 2015, singer Brendon Urie has been the only official member of Panic! at the Disco.

Question: what happened in 2015
Self-contained rewrite: what happened in 2015 to the Panic! at the Disco lineup