Before starting on ‘How to transpose down a perfect 5th’, make sure you spend some time reading how to transpose up a perfect 5th.
How do we know if we need to transpose up or down a perfect 5th?
This is a very important question and one that can be confusing if not taught clearly from the beginning.
Let’s think about our French horn… When the French horn plays a C we hear an F.
That means the French horn’s sounding pitch is a perfect 5th lower than the note they see on the music.
So, if you are writing out the French horn’s written pitch to sounding pitch you will be transposing DOWN a perfect 5th.
Therefore, if you are transposing up a perfect fifth you are writing it the other around. i.e. from sounding pitch to written pitch!
Make sure you are very clear on which way you are transposing.
If you are going from Written Pitch to Sounding Pitch you are transposing DOWN
If you are going from Sounding Pitch to Written Pitch you are transposing UP!
Let’s explore transposing down a perfect 5th
Below we have a melody in the key of C major.
What note is five notes below C…
You are correct! It is F!
We could also have used our circle of fifths…
So what is the key signature of F major?
The key signature is one flat. Let’s now apply this to our melody. Remember to change the key signature and then move each note down a 5th!
Let’s try a different key!
What scale is the below melody written in?
That’s correct, four flats means we are in the key of Ab major.
What is a perfect fifth below Ab?
That’s correct, it is Db major!
Db major has five flats so let’s draw this out below and move all the notes in the melody down by a perfect 5th!
What about our accidentals?
As before with our other transposition articles, remember your accidentals need to be treated separately.
Make sure to check these separately by asking yourself, is my top note in the scale of my bottom note?
Remember, even if the first note in your interval is higher, you must ask yourself if the top note is in the scale of the bottom note.
Look at the two notes below
In order to check this interval we must ask ourselves whether Eb is in Ab major?
Why? Because Ab is the lower of the two notes (even though it is written on the stave after the Eb!)
Let me know how you get on with your transposition journey in the comments! And if you have any questions don’t hesitate to ask!