kids and music

my 11-y-o had a BTS phase that lasted about three weeks. he's now listening to popsmoke. ffs

slippery slope

Any recommendations for apps or interactive websites for kids to start to learn the basics of music? Note values, rhythm, rests, and on from there... Seven-year-old will be starting his first piano lessons in a couple of months and I would like to give him a better foundation before he starts. I've taught him some of it but I'm no music educator. Barely a musician at all.

Or even youtube videos or series of good quality?