The word for this teaching just means "the sung." History produced a great many texts by that description — songs attributed to a fierce wandering ascetic, to a sage instructing a king, to the elephant-headed god, to a swan, to a goddess, dozens of them across the literature, each one needing its own qualifying name to be told apart from the rest. Only one of them dropped the qualifier entirely. Say simply "the Song," in most rooms where the word is used at all, and everyone already knows which one is meant.
Even its full name is oddly unspecific for a text spoken by one particular teacher. It could easily have carried his given name the way most of the others carry theirs. Instead it is named for the divine as such — a title any tradition could stand under, not the biography of a single teacher. That may be part of why readers from traditions with no prior stake in it have kept independently taking it up over the last two centuries, translating it into most of the world's major languages, each finding something in it that did not require sharing the rest of its original context to use.
Structurally, it sits inside a specific stretch of a much larger epic — a war narrative many times its length, of which this teaching occupies one contained section. And yet the tradition it belongs to treats it as one of three foundational texts a serious student is expected to know, standing alongside a set of older philosophical dialogues and a further, denser set of aphorisms — short enough to read in an evening, given the same structural weight as far longer works on either side of it. Its own closing line, repeated at the end of every one of its eighteen books, counts it among that older philosophical literature outright — an unusual claim for a teaching embedded inside a story rather than standing alone.
A teaching given at the edge of a battlefield, about crossing an ocean of grief, ended up read the way an ocean is read: brief enough to be carried anywhere, and dense enough that careful readers still argue, honestly, over which of its own three centers it most means to be about.