Nightingale in Scotland

Hi

I've been trying to identify a bird song in my garden for ages. For a few years a bird comes in summer and signs in the young trees in the field at the back of my garden.

I always thought it sounded like a nightingale but as I'm in the Scottish Highlands it seemed unlikely.

I saw it today and also caught a recording and I'm 99% sure it's a nightingale.

Is this unusual to have them so far North? The distribution maps seem to only place them in the South.

Thanks so much!