Here is a link to a BBC radio programme about doppler effects…
https://www.bbc.co.uk/programmes/b090xv6w
and there’s a short film clip to go with, here
https://www.bbc.co.uk/programmes/p05bxzhh
It turns out that the very first scientific experiment to show the doppler effect was carried out by trumpet players on a train…The sliding brass sound of the doppler is lovely.