You must complete Keyboard Setting: Tones and Semitones; Enharmonic Notes to unlock this Lesson.



  1. Perfect Interval
  2. Augmented Interval
  3. Diminished Interval

Perfect Intervals

There are four types of perfect intervals. These include unison, fourth, fifth, octave (eight).

Perfect Unison:

This is also called ‘prime’ interval. The notes of a unison are at one place, either on a line or a space on the stave. It does not contain any semitone. In a vocal music, two or more parts may be sounding the same note at the same time as unison.

Perfect intervalsPerfect Fourth (4th):

A perfect fourth contains five semitones. In a perfect 4th, four letter names are involved, e.g. C – F involves C, D, E, F.

All 4ths are perfect except one. The interval of 4th between F – B is more than a perfect 4th by a semitone. It contains six semitones instead of five. Thus, it is an augmented 4th. It is also called “ tritone” Because it contains three whole tones, e.g.

Lesson tags: JSS2 Music, JSS2 Music Evaluation Questions, JSS2 Music Evaluation Questions Second Term, JSS2 Music Objective Questions, JSS2 Music Objective Questions Second Term, JSS2 Music Second Term, Music Lesson Notes, Music Objective Questions
Back to: Music – JSS2 (Upper Basic 8) > Second Term
© [2022] Spidaworks Digital - All rights reserved.