Gregorian Chant is a series of letter segments where a choir chants the letter of the day. These segments appeared as early as Season 26. H is the only one that is not available on Sesamestreet.org
- A (fanon)
- E (Video: Alphabet Jungle Game) (aka Elmo)
- K (fanon)
- P (fanon) (to be made)
- T (fanon)
- X (fanon)
- The background for each letter is designed by English textile designer William Morris.
- E - Acanthus (1875)
- G - Honeysuckle (1876)
- H - Sunny Rug
- I - Woodpecker (1885)
- E and I are the only vowels in the series.
- In the Alphabet Jungle Game, Elmo appears in the E segment. His lines are "E." "E for Elmo." and "Elmo."
- Running time of each segment is approximately 15 seconds.
- The typeface for E, G (capital only), H, and Z is Friz Quadrata.
- The lowercase g's typeface bears a resemblance to Futura Light.
- The typeface for I and J is Times New Roman.