This is a show about gender identity – and it opens with what, within the cloistered world of the Fringe, feels a comfortingly predictable scene. There are two young children; one's dressed in pink and one's dressed in blue; then one day, the one in pink realises that he's actually a boy. We're cool with that, right? Shall we nod and move on? Not so fast. That vignette is a trick, the too-simplistic story we're too eager to hear – the real story is still waiting to be told.

In truth, performer Ink Asher Hemp identifies as trans non-binary (neither a man nor a woman) – and while 147Hz Can't Pass isn't an autobiography, it's the story of the community of which they are a part. Perhaps it's appropriate that Hemp's performance also defies conventional classification; they include elements of theatre, performance poetry, and straightforward discussion, melding occasionally with video clips cast onto a screen.

The early scenes are a tumble of words – words you have to grab and hold onto, lest their full impact pass you by. But the concentration involved is really no effort at all; Hemp's delivery and charisma draw you into their narrative, make you burn to know more about the tricky path through life they're describing. As they speak, their movements are staccato – nervous and fidgety – not through discomfort at telling the story, but because anxiety and pressure lie at the heart of the story being told.

Later passages are more poetic, more rhythmic, more evocative; almost soothing in their gentle pattern, though the feelings they're describing aren't comforting at all. A couple of video interludes add some variety, with well-worked interventions from Hemp bridging the gap between the screen at the stage. And at times Hemp drops the mask of performance to speak to us directly: sometimes to explain simple, practical things, like the reason why – even if nobody else cared which toilet they used – it would still matter to them that there's a gender-neutral one.

There's searing raw honesty throughout the piece, but it's tempered by deep thought and understanding. The understanding shows in the way Hemp speaks to us: not as antagonists who must be shown the error of our ways, but as fundamentally nice people who just haven't been prompted to work this through before. The thought, meanwhile, is reflected in Hemp's frequent selection of beautiful, perfect metaphors. See, for example, how gently they point out that it's not for me to propose solutions: "support comes from beside, not in front," they say.

So why's it called 147Hz Can't Pass? When it comes to marketing, the curious title won't do the show any favours – but each word is meticulously chosen, and explained on a slip of paper for you to take away. And everything about 147Hz Can't Pass feels like it's judged with the same exquisite care: it isn't a cry of pain or an appeal for acceptance, but a series of eloquent facts, offered so that we can understand them.

I do understand now – not everything of course – but much more than I did before. And, just as importantly when it comes to that five-star rating, I've also watched a masterful hour of mesmerising spoken-word theatre.