Children's Alphabet is a live-action Sesame Street segment. The children on a playground form every letter of the alphabet. When one letter gets dissolved, it fades into the next shot with the next letter being already formed by children. Only the uppercase version was made. The lowercase version is not made. Starting as early as Season 25, a new version of this segment is introduced. It is the same as the original, but has background music added, and sometimes the ending is edited. The background music version was also used for the rest of the appearances of this segment.
In Episode 3659, this segment plays until it reaches W, when it abruptly cuts to Scene 4. After Scene 4 ends, the segment resumes, skipping X with children waving flags.