Songs are different from code, in that the “hook” that makes the money may be only a few seconds long. There are many creative choices that a songwriter/producer can fit into just a few seconds: the harmony, melody, rhythm, lyrics, timbre, effects, ...
Whereas for code, the space of creativity is limited by functional considerations. A creative choice is protected by copyright but not all choices that programmers make are creative. Often the choices are limited by the API/interface or by efficiency considerations and it turns out that there’s only one good way to do something.
A function may be very intricate, yes, while still containing almost no creative value (e.g. a Vulkan setup function). Music doesn’t have an equivalent to this - the placement of every note is a creative act.
Courts have held that it doesn't apply to music, why do you think different rules apply to code?