A 2kHz C-humm

The day after the rain has been gorgeous. The air is extremely humid and the sky has been a bit hazy with high clouds shading the direct sunlight.

I've had plenty to do indoors today or, as it turned out, on the veranda in the shade. I've got some concerts coming up in August so there's a lot of material from my last two concert programs to keep up to date, plus a couple of new concerts that needs new content. While sitting on the veranda I might as well do the laundry as well, that's not too much extra work but it makes me feel like I'm doing a lot.

The evening walk was set towards The Garden in the forest. It's been a while since I was there, it's such a peaceful place, as you might see in the extra, showing the entrance into The Garden.There are four field like this one, each very different to the others and there are always new things to discover. 

Like today. As soon as I entered The Garden I noticed a sound I don't normally hear in there. A distinct note, that I could hear and also decide the general pitch of. It was the note C, the one to the left of the two black keys on a piano, quite high up, past the middle of the piano. If you could measure the frequency of the vibrations you would find they were in the spectrum of between 1000 and 2000 kiloHertz or, 1-2 kHz in short. I perceived it as a note but it was really more like a humming noise, with a general pitch of around 2000 kHz, or a 2 kHz humm of a C. 
The garden is surrounded by very old Linden trees in full bloom, an irresistible scent for miljons of wild bees. The picture doesn't do the experience justice at all, my mobile camera isn't constructed for this kind of thing. I assume you can use your own imagination.