Another favorite from our own childhood "Puff the Magic Dragon" but if you know the song it has a very somber ending so we found a new ending that we absolutely love.  We encourage our kiddos to get comfy, snuggle a blanket or stuffed animal or to move side to side with us to create a calming and accessible environment to self regulate to.  Not mentioned in the video but if your student needs to move during this experience, encourage them to move like a ballerina to increase auditory awareness (for example we're not in a mosh pit during this song).  We added gang vocals to stimulate a children's choir feeling for the choruses.