'Peter and the Wolf', by Prokofiev. Pretty much anything by Prokofiev really or JS Bach.
Or the 'Lord of the Rings' soundtrack, all three of them, they're very good.
Personally, my go-to has always been Jeff Wayne's 'War of the Worlds', but you said fancy classic stuff.
Or Timmy Mallet's 'Incy Wincy Teeny Weeny Yellow Polka-Dot Bikini'; I prefer his earlier stuff before he sold out.