How to transpose down an octave

By Jade Bultitude
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In the last transposition blog, part 4, we discussed how to transpose up an octave between the four main clefs, treble, bass, alto and tenor! 

If you haven’t had a chance to read the previous Transposition Basics post, take a look here!

This week we will look at how to transpose DOWN an octave. Let’s cover very quickly the basics of what an octave is… 

What is an octave?

An octave simply means eight notes. How many sides does an OCTagon have?! Eight!

octagon, eight notes, eight sides, octave

Now in the last blog post, we practised keeping the note the same between the clefs, before we looked at moving up an octave. This is an extremely important skill as it makes it a lot easier to transpose up and down between the clefs. Quickly, let’s first look at putting middle C into our various clefs just to remind ourselves what this looks like. 

Treble clef, middle C, Bass Clef, Alto Clef, Tenor Clef, semibreve, whole note, transpose, octave
Middle C in Treble, Bass, Alto and Tenor clef

We need to be clear where middle C is in all of our clefs. This is vital if you are to keep the note the same or transpose up and down an octave in different clefs. 

Let’s just check we can put the below bass clef note in each clef so it sounds the same. Which note do we have?

Bass Clef, Middle C, D below middle C, transpose, octave

We have a D below middle C. Let’s put this now into our other three clefs…

Transposing, D below middle C, Middle C, Treble clef, Alto clef, Tenor clef, transpose, down octave
D below Middle C in Treble, Alto and Tenor Clef

If you are happy with keeping the notes the same let’s now practice moving our notes down an octave. 

As before with up an octave, first practice transposing the note down an octave (eight notes) within the same clef. 

Which note do we have below?

Bass Clef, D above middle C

That’s correct, we have a D just above middle C! Let’s now take this D above middle C and transpose it down an octave to the D just below middle C!

Bass clef, D below middle C, transposing, transposition, transpose down octave
D below Middle C in Bass Clef

Easy as that! 

I’m confident with transposing my notes down an octave within the same clef, what now?

Once you can confidently move down an octave in the same clef it is now time to see if you can take this knowledge and move this between the clefs. 

Remind yourself how you took the same note into different clefs. For example, if we have middle C in the Treble clef, it would like this in all the other clefs. 

Middle C, Treble clef, Bass Clef, Alto Clef, Tenor Clef, transpose, clefs
Middle C in Treble, Bass, Alto and Tenor Clef

One more, if we have the A above Middle C, it would look like the below in all the clefs. 

A above middle C, Treble Clef, Bass Clef, Alto Clef, Tenor Clef, transpose down an octave
A above middle C in Treble, Bass, Alto and Tenor Clef

How can I use this knowledge to transpose down an octave in the different clefs?

Now let’s apply this to moving DOWN an octave between treble and bass clef. 

Which note do we have below in the treble clef?

Treble Clef, A above middle C, note A, semibreve, whole note

That’s correct, we have an A above middle C. 

Make particular note of the fact we say ‘above middle C’. By recognising this, you can then safely say that by taking it down an octave (eight notes) you will be writing the A below middle C. 

Firstly, let’s look at what this A would like in the Bass clef without transposing it. 

Bass Clef, ledger lines, A above middle C, whole note, semibreve, transpose
A above middle C in Bass Clef

That’s far too many ledger lines for my liking!!

Now let’s count down eight notes from here to find our A below middle C, an octave below the original note we were given in the treble clef!

Bass clef, A below middle C, Transposition, transposing, transpose down octave
A below Middle C in Bass Clef

Below you will see the original note in the treble clef on the left. On the right you will see this note taken down an octave in the Bass Clef!

Treble clef, A above middle C, Bass clef, A below middle C, transposing, transposition, transpose down octave

Shall we have a go at this question the other way around?

Which note do we have below in the bass clef?

Bass Clef, F above middle C, ledger lines, semibreve, whole note

That’s correct we have a F above Middle C. 

Find this F in your Treble clef (make sure it’s the same pitch!)

Treble clef, F above middle C, whole note, semibreve, transpose
F above middle C in Treble Clef

Now bring this down eight notes (octave)

Treble clef, transposition, transposing, whole note, semibreve, transpose down octave
Count down eight notes from F above middle C to F below middle C

What is our final answer?

F below middle C, treble clef, semibreve, whole note, transpose down octave, answer
Final answer without workings

Easy as that!

How do I go about doing this in the alto and tenor clefs?

Answering this question in the alto and tenor clefs is now very simple, just keep that middle C in mind. 

Let’s Try!

Which note do we have in the example below in treble clef?

Treble clef, E above middle C, semibreve, whole note

That’s correct, we have an E above middle C. Now see if you can find this same note in the Alto clef…

Alto Clef, E above middle C, semibreve, whole note, transpose down octave
E above middle C

Now simply count down your octave to the E below middle C!

Alto clef, semibreve, whole note, E below middle C, transpose
E below middle C

We can also do this same question in Tenor clef just as easily! 

Which note do we have below in the bass clef?

Bass clef, semibreve, whole note, G above middle C

That’s correct, we have a G above middle C. 

Find this note in the Tenor Clef…

Tenor clef, semibreve, whole note, G above middle C
G above middle C in Tenor Clef

Now as before, count down your octave (eight notes).

Tenor Clef, semibreve, whole note, G below middle C, transpose down octave

How easy is that?! The more you practice doing this the better you will get, eventually you will be able to do this much quicker! 

If you have any comments or ideas, as always, let me know in the comments!

Next time we will move further on this transposition journey… watch this space!

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AUTHOR
Jade is an experienced musician and teacher as well as being the founder of Music Theory Foundations. She has been helping people learn music theory for more than 10 years from pre school children all the way to degree level studies.