I just got a really nice razor from ebay, a Marks & Co 10-6/8 Fontana. Marks isn't a BIG name and searching SRP only returns 3 hits, but there wasn't a discernible hone line on the spine and the little fountain inlay on the handle looked cool and nobody else was bidding so...

After I cleaned a thick layer of dirt and grime I tested the edge on my arm hair, it was about as sharp as really sharp pocket knife, better and better.

When I first pushed the blade into the thousand grit, it made a high-pitched ringing sound, likewise on the strop it made a kind of ringing instead of the wisk-wisk I'm used to.

It also sounded very different when I shaved with it.

Is this one of those "singing" razors I've heard of?

All of my others are full hollow too, but are narrower and lighter than this one.