I think the more ways information has to get into your brain, the more likely it is to stick and be understood. Music and singing is important as it exercises a different area of the brain than raw thinking and memory. Muscle memory is important, too, so (I think, for me) writing notes is vital for learning in a lecture.
But singing the alphabet by itself can be confusing. I remember being baffled for a long time about what "elemenohpee" was. :-)
Cheers,
Scott.