There is a ton of science and information about the connection between music and language. The field of music therapy began 50 years ago. Music therapy is "The scientific application of music to make changes that are non-musical - physical, emotional, cognitive" Music is something that every brain can understand. Music stimulates the entire brain. For detailed information about how the brain responds to music, see these neurological music therapy informational videos by Nicole Jacobs on YouTube.
You will find many, many videos on this subject on YouTube. I like these because I think they are very informative on the entire subject of Neurological Music Therapy.
Based on the science and my eye opening training by Julie Guy of The Music Therapy Center of California, I incorporated music, songs and rhythms whenever I could. Singing a specific tune during specific transitions worked famously. I went further and created songs for activities and concepts.
I went even further and published a DVD with music and video to countdown transitions. If you don't have a way to get music therapy for your child, incorporate music whenever you think about it.