# Need some simple help with Perfect Intervals



## Amadeus Tentacles

So I am very confused on this and I have looked around alot in my textbook for a better explanation but I cannot find it. 

The questions ask me to name all the perfect intervals. The examples the text's says they are all perfect (Unison, 4th, 5th, and 8ves of course). So I looked through the questions, and in the back of the book its says questions 4. and 7. are not perfect intervals and I am here to ask why is this? Here are the two questions I dont get. 

No. 4 is In (Bass Clef) from A to E Flat I know this is a 5th so why is it not perfect. Is this just considered diminished? And if so why is it diminished? 

No. 7 Is (Bass Clef) from D Flat to A. Again why is this not a perfect interval? 

I need an explanation because I can not figure it out haha I know its extremely elementary. Any help would matter alot to me  thank you again! and if anyone could maybe link a better explanation of intervals I would like that also .


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## Kjetil Heggelund

A perfect 5th consists of 3 whole steps and 1 half. In no. 4 you have only 3 whole therefore is diminished 5th, no. 7 has 4 whole steps and is augmented


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## EdwardBast

The number of the interval is determined by how far apart the letters are, irrespective of sharps or flats. Thus any kind of D up to any kind of A is a fifth. D to A is a perfect 5th (7 semitones). D to A-flat is a diminished 5th (6 semitones). D to A-sharp is an augmented 5th (8 semitones). However, if one spelled the same 6 and 8 semitone intervals differently, they would no longer be fifths. D to G# is an augmented 4th, even though it sounds the same as D to Ab. D to Bb is a minor sixth, even though it sounds the same as D to A#. An even stranger example would be Cb to D#. These notes are 4 semitones apart, but the interval is still a 2nd, a doubly augmented 2nd. Why? Because C and D are one letter apart.

The best answer to your question, however, is play them on the piano or hear them in your head! Perfect fifths sound smooth and open. Diminished fifths sound tense and dissonant.


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## Nate Miller

Edward answered this pretty well, so I'll just pass along what my old teacher used to always tell me when I asked these sort of questions...

"because music is hard and tricky" :lol:


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## Amadeus Tentacles

Thank you everyone that replied! Makes a lot more sense now! I don't have a teacher right now so on my own it's pretty tricky haha


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