The soundtrack released by Back Lot Music on October 12, 2018, received positive reviews from critics, who praised it for its balance of softer melodic passages and powerful themes.

Chazelle liked the theremin's association with low-budget sci-fi pictures of the '50s and early '60s, as according to him, "Armstrong and his NASA colleagues were, in their race to the Moon, basically doing real-life science fiction".

"[4] Hurwitz acquired a theremin and learned how to play it, and his performances are in the final score, as he wanted to "sound electronic, but not harsh or abrasive" and tried to make it, in most places, mildly to blend with the orchestral music.

of vintage Jerry Goldsmith to a rare burst of full-thrust power when the lunar surface is first glimpsed up close, the quiet majesty of the drama owes much to the infinite moods of the score".

[2] Scott Snowden of Space.com wrote "The instrumental score by Justin Hurwitz – on more than one occasion – was reminiscent of the wonderful soundtrack by Philip Sheppard to the series Moon Machines (2008) and like that underrated TV show, the music is utilized to great effect in this movie.

"[3] Zanobard Reviews called First Man score as "pretty spectacular" and opined "The way Justin Hurwitz perfectly captures the mysterious and suspenseful nature of space is superb, and at points you really feel just how awed and at the same time terrified the astronauts must have been as they rocketed towards the Moon, so he did a great job there too [...] The score builds-up its themes incredibly well, but it takes a long time and so makes for a very dull forty minutes before the music finally kicks into gear with the likes of Apollo 11 Launch and The Landing.