How about a vinyl record of one of his favorite post-rock bands? He can enjoy the music on a record player and start his own collection. Another idea could be concert tickets to see a post-rock band in person or a magazine subscription to a music publication that covers the genre. You could also consider a book on the history of post-rock or a guitar pedal that can create post-rock sounds.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.