Somebody sang an old Canarian song on Playa de Las Teresitas and I hummed along

I was lying on the black sand at Playa de Las Teresitas in the afternoon when a man two towels away started singing under his breath, an old Canarian song, slightly flat. Without realising it I was humming along. He looked over and grinned. We did not speak. At the end of the song we both applauded softly, once. I looked up the song that night. It has four verses. I know three. I have sung it in the shower for two weeks. I think the man would approve of the shower.