Fifth
Glossary
        
          
The fifth or perfect fifth is a consonant interval with a ratio very close to 3:2. See also diminished fifth and augmented fifth intervals and Pitch & Intervals.
The inversion of a perfect fifth is the perfect fourth, so they share an interval class.
Referring to roman numeral function, “fifth” can mean the V chord of a key.
        
      
       
    
The fifth or perfect fifth is a consonant interval with a ratio very close to 3:2. See also diminished fifth and augmented fifth intervals and Pitch & Intervals.
The inversion of a perfect fifth is the perfect fourth, so they share an interval class.
Referring to roman numeral function, “fifth” can mean the V chord of a key.