Hilariously brilliant. It reminded me of the Siemens Taurus' musical scale acceleration sound, probably because I tried to record one (semi-successfully) a few days ago in action from my room's window.
Here's a video explaining what I mean. It's not my video, mine turned out a lot worse as the locomotive didn't make the full scale, just three different tones.
an MaK G 1206, built here in Kiel