Getting to Aldeburgh as the sun set, in civil twilight, a burst of red across the low clouds, and the moon, pale and waxing still but up since 3pm, was growing stronger. It was a ‘must get a swim’ drive. To get to swim before the most precious light –twilight with a growing moon and clear sky – disappeared. Aldeburgh is special again. I drove to the water front, in a familiar hurry to see the sea, sky and shingle. I shuffled across the deep shingle, mostly stones the size of a thumb, and settled to change on a ledge of shingle. The time and place were even righter than I thought before – the echo-crash of waves across the beach from right to left was something new – the sea was singing, the water was music, percussive, resonant music. A sound I never knew before. I thought to Benjamin Britten, who was drawn to Aldeburgh, wrote many works, wrote an opera, Peter Grimes, set in the Borough / Aldeburgh really. His young person’s guide to the orchestra, the percussion movement. Britten could not not have heard this sea music. The explanation for this added wonder – of music to the moon and sky and water came with an engineers way of thinking – how does it work? My best guess was that the tide having half come in was pushing in smaller breakers against the shingle – the size of the waves and the height of the ledge were right to set up a ‘schzzzhhaaa-boom’ echo rippling across the beach from right to left as the waves hit the shingle from right to left. An as an audience of one, I realised that I had the perfect seat.