This one has been out in the ether for a little while now, but somehow I hadn't seen it. Which means that I hadn't lived, because damn.
Thankfully, Journey composer Austin Wintory linked to a similar video of another person performing the Harry Potter theme (equally impressive, so I'll embed it below), and I went down a YouTube rabbit hole watching videos of glass harp performances.
It starts out nifty enough, then gets fully ridiculous about halfway through. I think that just about every famous Mario sound effect gets hit.
And here, check out that Harry Potter performance, which I believe is by a different performer (I've unfortunately been unable to track down the performer's name.)