This is a relatively new synthetic musk made by the Swiss company Firmenich. I have been testing a sample of it, and find that it is one of the nicest-smelling and most versatile musks that I have tried. It lies somewhere between the typical "white musk" fragrance of many synthetics and the rich fragrance of natural ambrette. In fact, picking up the sillage from the test strip at a distance after about 2 weeks of drydown, I'm almost fooled into thinking that there is ambrette somewhere in the room. Helvetolide also has a slightly fruity side to it, which makes it seem fuller and less one-dimensional than some other synthetic musks. It can function as a top and middle note as well as a base note.