Kermit performed the song at the 52nd annual Academy Awards in April 1980. Billboard's Andrew Unterberger chose that performance to kick off his not-to-be-missed 2017 list The 100 Greatest Awards Show Performances of All Time. Unterberger saluted the performance with a line as modest and unassuming as the song itself. "Not exactly the most hi-octane of displays -- just a frog on a log, probably not even singing live -- but easily as endearing as any performance with a fire pit or post-modern video montage has ever been."
That gets at the song's appeal: "Rainbow Connection" endures for the same reason that "The Way You Look Tonight" (1936, written by Dorothy Fields and Jerome Kern) and "What a Wonderful World" (1967, written by Bob Thiele and George David Weiss) endure. They're understated. They're not overly sentimental. The songwriters and the artists who introduced them (Fred Astaire and Louis Armstrong, in the case of the last two songs I mentioned) got the memo that sometimes less is more.
"Rainbow Connection" is a children's song that doesn't talk down to children in the slightest. Williams has said that his favorite lyrics in the song are "Who said that every wish/ Would be heard and answered/ When wished on the morning star?/ Somebody thought of that/ And someone believed it/ Look what it's done so far." Little kids won't grasp the wisdom in those lines; they'll likely be lulled by the soothing lullaby. But older kids and adults will get it.
A couple of generations have grown up on "Rainbow Connection." Anyone under 50 grew up listening to and loving the song from childhood. The song has been featured on many children's albums and collections of lullabies. Kenny Loggins included it on his 1994 album Return to Pooh Corner. Sarah McLachlan recorded it for the 2002 compilation For the Kids. Jason Mraz recorded it for the 2004 sequel For the Kids Too! Weezer teamed with Hayley Williams to record it for the 2011 compilation Muppets: The Green Album. Jim Brickman included it on his 2012 album Piano Lullabies. Gwen Stefani recorded it for the 2015 compilation We Love Disney. Lisa Loeb recorded it for her 2017 album Lullaby Girl.
Kermit the Frog reprised the song on The Muppet Show in 1980 as a duet with guest star Debbie Harry. Kermit also reprised the song in the 2011 film The Muppets, this time as a duet with Miss Piggy. In 2018, Kermit teamed with Maddie Poppe for her performance on the finale of American Idol. (Following Henson's untimely death in 1990, at age 53, Kermit has been voiced by other actors.)
Judy Collins was the first major artist to record the song, for her 1980 album Running for My Life.
Williams and Ascher had success together prior to writing the music for The Muppet Movie. They co-wrote "You and Me Against the World," which was a top 10 hit on the Hot 100 for Helen Reddy in 1974. It brought them a Grammy nom for song of the year. They co-wrote four songs for the 1976 soundtrack of A Star Is Born, including "Watch Closely Now" and "The Woman in the Moon." (Williams teamed with star Barbra Streisand to write the film's biggest hit, "Evergreen (Love Theme from A Star Is Born)," which won an Oscar for best original song and a Grammy for song of the year.)
Williams and Ascher received a Grammy for The Muppet Movie (best recording for children), though "Rainbow Connection" wasn't a big enough hit to give them a serious shot at a song of the year nomination. Williams had been nominated in that category three times, for "We've Only Just Begun" (1970) and the aforementioned "You and Me Against the World" and "Evergreen."
Williams and Ascher received a second Oscar nom for their work on The Muppet Movie in the category of original song score and its adaptation or adaptation score. (Ralph Burns won for his work on All That Jazz.)
Carpenters, who had major hits with three songs that Williams wrote with his then-partner Roger Nichols ("We've Only Just Begun," "Rainy Days and Mondays" and "I Won't Last a Day Without You") recorded "Rainbow Connection" in 1980, but shelved it. Richard Carpenter finally released their lovely version on the 2004 collection As Time Goes By.
Williams was voted into the Songwriters Hall of Fame in 2001, on the strength of instant standards like "We've Only Just Begun" and "Evergreen," and also quieter, sleeper successes like "Rainbow Connection," the little song that could.