Now that I have a song from Sesame Street stuck in my head, I'll talk about songs in general. When K was little, I was constantly singing, and it always seemed to calm him. If I couldn't get to him right away, I'd start singing, and he'd usually calm down until I could get him. We'd change the words to songs to make them about him at times. The one song I knew would almost always calm him was "You Are My Sunshine". He still likes for me to sing it to him at night sometimes, or if he's upset. He's also quite musical, and loves listening to jazz, Vivaldi, Clapton, and Michael Jackson. He really loves playing on his toy piano, and frequently asks C to sing a song with him.
Speaking of C, she's never responded the same way to music that K does. If she gets upset, a song isn't going to help. Sometimes I can get her to calm down a little with "Hush Little Baby", but not always. She does like listening to music, she just isn't going to be fobbed off with a song. She's generally calm, so when she cries, she means business. She does enjoy "singing" with K, though.
Now for the Sesame Street video