First recorded by The Laurels (1958).
Hit version by The Echoes (US #12/CAN #8 1961).
From the wiki: “‘Baby Blue’ was written by Long Island assistant high school principal Sam Guilino and music teacher Val Lagueux. Brooklyn vocal group the Laurels (not to be confused with the Laurels who first recorded the similarly-titled ‘Baby Talk‘ in 1959) cut ‘Baby Blue’ in 1958 as a demo but couldn’t find any takers for the song. A bit more than two years later, in early 1961, the Laurels replaced a couple of members, changed their name to the Echoes, rerecorded ‘Baby Blue’ and had a hit.
“The Echoes’ single spent 12 weeks on the Billboard Hot 100 chart peaking at #12.