Real world article
(written from a production point of view)
"California Dreamin'" is a pop song written in 1965 by John Phillips and Michelle Phillips (who later guest starred in the Star Trek: The Next Generation first season episode "We'll Always Have Paris"), and originally performed by their band, The Mamas & the Papas.
The song was featured in the Star Trek: Picard second season episode "Assimilation", performed by the German DJ/remixer Freischwimmer. It played over a montage of establishing shots of Los Angeles County locations in 2024.