Half-serious group?

• Quintet to which "y" is often added
• Facetious group?
• Vowel quintet
• The five vowels
• Group that ends "... and sometimes Y"
• Facetious string?
• Elementary school quintet
• Key parts of a so-called supervocalic word
• Facetious fivesome?

Wikipedia Word definitions in Wikipedia
' AEIOU ' is a 1979 Czechoslovak film. The film starred Josef Kemr .