When the alphabet is learned in one long song, it usually means that for a child to know what letter "comes next" they typically need to start at /a/ to figure it out. This is time consuming and really means that they don't know the alphabet sequence very well at all. Accordingly, I always teach the alphabet in four segments: a-g, h-m, n-t, and u-z, one at a time, sequentially, cumulatively and in a fun way.