Famous children's song that shares its tune with another famous children's song

• Intro-level info
• Basic preschool learnings
• They're not advanced studies
• Alphabetic basics
• Introductory material
• They contain the sequence "s, t, u"
• Rudimentary run
• Beginner's topics
• Like the first thing you learn

Wiktionary Word definitions in Wiktionary
init. The callsign for the Ceduna station of the Australian Broadcasting Corporation