We're all used to flat and sharp signs, also naturals. Accidentals in some cases. But why those unusual signs? I suspect the b may have something to do with the German B, but the # sign? Something to do with the German H? Otherwise known as hash, or, properly 'octothorpe', coined by a telephone company in the '60s. And the natural seems to almost be a mixture of b and #. What's it all about?

We're all used to flat and sharp signs, also naturals. Accidentals in some cases. But why those unusual signs? I suspect the ♭ may have something to do with the German B, but the ♯ sign? Something to do with the German H? Otherwise known as hash, or, properly 'octothorpe', coined by a telephone company in the '60s. And the natural ♮ seems to almost be a mixture of ♭ and ♯. What's it all about?