Tom Chapin
https://www.tomchapin.com/
Lyrics: credited as “Traditional”
Melody: Franz Lehar
https://www.tomchapin.com/docs/lhb.html
https://en.wikipedia.org/wiki/Franz_Leh%C3%A1r
From Wiki: Chapin is known for the song “Happy Birthday”, released in 1989 in his Moonboat album. It takes its melody from “Love Unspoken”, a song featured in the opera The Merry Widow, the most famous operetta by the Austro-Hungarian composer Franz Lehar.
Personal connections: Kaitie’s preschool teacher, whom she’s still friends with, has called her every year she can remember (maybe since 1989?) on her birthday to sing this to her over the phone.
Sara learned it in CCLT (which overlapped with her own birthday) in 2023.