Git presents things to you as patches, but it doesn't really uses patches internally [1], so having a specif diff program doesn't help - except maybe to get readable patches - because IIRC, this can be customized.

A version control system that would/is using patches internally would be more space efficient, but probably slower as it would have e.g. to apply all patches from version 0 to reconstruct the current version. Git made its choice with regard to this frequent dilemma and its original purpose, which was to version control the Linux kernel source code.

> If changing a single bit at the start of file changes the whole thing then it's really a failing of the file format. By which I probably mean the container format.

Audio formats are typically compressed, so this is hardly avoidable. Compression is a bit like encryption in that regard, except that (good) encryption deliberately introduces random data [2].

[1] https://jvns.ca/blog/2024/01/05/do-we-think-of-git-commits-a... (or long story short:) https://news.ycombinator.com/item?id=13644631

[2] https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation