Songfacts®:

• This song is used by Julie Andrews' character, Maria, in the film and stage production of The Sound Of Music, to teach the notes of the major musical scale to the Von Trapp children. Nowadays this is frequently one of the first songs that children will learn to play on simple musical instruments.
• An 11th century monk Guido D'Arezzo wrote the words to the mnemonic, although the original, taken from a medieval Latin poem, begins "ut (rather than do), re, mi, fa, so, la." D'Arezzo's tune was different from the Sound Of Music version, but used the same system of ascending notes. He based his tune on an anthem for Saint John.
• The musical scale Do-Re-Mi sings the notes of the C major scale, but this song is actually in another key, which is B flat. >>>

  Suggestion credit:
  Miguel - Guayaquil - South America
• Here's the Saint John's Anthem where Guido D'Arezzo created the musical notes:
  
  UTqueant laxis
  REsonare fibris
  MIla gestorum
  FAmuli tuorum
  SOLve polluti
  LAbii reatum
  Sanct Ioannes
• Madonna references this song in her 1992 track "Deeper and Deeper" with the lyrics "When you know the notes to sing, you can sing most anything."
• Judy Collins sang this during a season 2 appearance on The Muppet Show as a piano/vocal duet with Rowlf the Dog. It showed up again the following season when Kermit and the Glee Club sang a version that spiraled out of control.
• This was used in the Full House episode "Terror In Tanner Town" (1990) when Danny attempts to gather the family to meet his new girlfriend and her son. Jesse says, "What is this, a Julie Andrews movie?," leading the group to mock Danny's efforts with a singalong of the tune.
• In a 1993 episode of the Canadian sketch comedy show Kids In The Hall, the cast sang this to cheer up a boy who lost his dog.