There are many versions of the classic Carnival of the Animals, first performed in 1886. The entire composition is delightful. The Swan is the thirteenth of fourteen movements Saint-Saens wrote for it. It may affect others differently, but has always had a calming effect on me. I think of reliving important moments and reflection on life. This particular version is highly skilled and nearly flawless, with very smooth transitions and perfect phrasing.
It should be played with good headphones or with high-quality speakers to give the feeling of being surrounded by the music as in the good seats in a concert hall. Darkness is a good accompaniment, but at least close your eyes or darken the screen so the images do not distract. Think of it without a title. If it were known as Etude #11, what does it suggest to you? In your mind, picture a swan on a lake toward dusk if you like, or just let your brain translate the sound directly into emotion. Outside suggestions are not required.