This 2017 video says about itself:
The Song & Calls of the Blackcap
It’s always a joy to hear the song of the blackcap as it returns and adds its voice to the growing chorus of spring bird-song in the garden and nearby woods. The video uses spectrograms to help visualise the form and sound of the song.
Today, arrival in Egmond Binnen village.
Blackcap, blackbird and chiffchaff singing.
Dear Kitty. Some blog 