I saw Metallica in concert with an orchestra. Does that count?
I would call “Enter Sandman” as classic music.
When my now 25 year old son was a baby we would put him to bed and play the Peanuts Christmas Special CD every night. I found it very relaxing myself. Even as a toddler we would put him to bed and start that CD. I sometimes fell asleep on his bed after reading him a story.