How I Miss My X

From Muppet Wiki

Sung by Patti Labelle at a nightclub, singing about missing her letter X, with flashbacks illustrating their good times and relationship. After the song is over, the letter X appears from the audience, and she is reunited once again. Patti gives the letter X a kiss, and everyone applauds.

In addition to being performed on Sesame Street, this segment was also shown in The Sesame Street Special.