Brian Wilson famously churned out era-defining summertime hits, all while battling mental illness and personal demons.

"Caroline, No" was released as the first solo Brian Wilson song in 1966, and then appeared as the closing track on the legendary Beach Boys album Pet Sounds. The melancholy lyrics and creative instrumentation—including harpsichord, vibraphone, a tambourine hit with a wood block and a water jug hit with a mallet—is classic Wilson.

Chunks of work by the Beach Boys’ founding genius went unpublished during his tumultuous life. Here’s a look at his phases and some pieces likely to be released.