How to Transpose Down a Major Second: A Music Theory Guide

Transposition is essential skill for any aspiring musician. At their heart of it, transposition allows you to alter music so that it can be played on different instruments or in different ranges of pitch.

So let’s take a dive into how to transpose down a major second, both for music theory students and for musicians seeking to understand the concept of transposition

Need to transpose using another interval; check out all our transposition guides here.

Why transpose Down a Major Second?

We say that the clarinet is an instrument ‘in the key of Bb’ and this simply means that when the clarinet plays a ‘C’, the listener will hear a ‘Bb’. So, for example, if a Clarinet in Bb is playing a piece written in the key of C major (no sharps or flats) we will hear the piece in the key of Bb major (two flats)!.

It is important to learn how to move between written pitch (the notes that the performer sees on the music) and concert pitch (what we, the listener, will hear). For the clarinet this means transposing down a major second to get from written pitch to sounding pitch.

What is a Major Second?

A major 2nd interval is created when we move from the 1st degree of the scale to the second degree to the scale. This interval is called a ‘major’ second because it is the 2nd note of the major scale. Another way of thinking about a major 2nd is that it is a whole-step above the lower note.

3rd, 6th and 7th intervals can also be major or minor, whereas 4th and 5th intervals are described as ‘perfect’.

How to Transpose Down a Major Second

This method has three steps:

1. Transpose the key signature down a major 2nd
2. Move all the notes down a 2nd
3. Deal with the accidentals

(If you thought we could transpose each note one at a time, click here to see why NOT to do this)

Remember we said that we transpose down a major second when we think about the clarinet. This is because when the clarinet plays a C, we hear a B flat.  

Let’s think about that…

We see a C

We hear a Bb

So if we have the written pitch, what we read, then we can transpose this down a major 2nd to find the sounding pitch, what we hear.

Have a look at the melody below and let’s transpose it down a major second. 

Step 1- Transpose the Key Signature

First, let’s transpose the key signature. Our melody is the key of C major, so what is a major 2nd below C natural?

As you can see above, a major second below C is B flat. This means that we now need to put the key signature of B flat major at the start of our melody. 

The key signature of B flat major has two flats- Bb and Eb.

Here it is in our melody.

• If you are still unclear on your key signatures, please make sure you are familiar with your Circle of Fifths. 

Step 2- Move the notes Down a 2nd

Once you have changed your key signature, we then need to follow this with moving all the notes in the melody down a 2nd. As with all intervals we include the starting note, so effectively this means moving the notes down once. 

And we have our transposed melody! We can see what the written pitch is (what the player reads) when we would like to hear the melody in the key of C Major (the sounding pitch).

There are no accidentals in this melody so no need for step 3 this time.

Example 2

What key is our melody in below?

That’s correct, we are in A Major!

Step 1- Transpose the key signature

First let’s transpose the key signature. Can you transpose down a major 2nd from A?

The 2nd note of the G major scale is A natural. This means we now need the key signature of G major. G major has one sharp – F#. 

Here is the new key signature at the start of our melody.

Step 2- Move the Notes up a 2nd

Now we have changed the key signature, simply move all of your notes down a 2nd. 

As you can see, we have not moved the G sharp note yet. This is because it is not in the notes of the original key signature and so will need to be treated differently.

Step 3- Accidentals

In our original melody we have a G#. This note is not in the key of A major and so it will not be transposed correctly be the first 2 steps.

To transpose this note we treat it on its own. We can ask: what is a major 2nd below G#? The note below G is F but G# is not in the F major scale. However G# is the 2nd note of the F# major scale, as shown below.

Here is the final transposition alongside the original melody.

Suppose we didn’t know that F# major had six sharps, is there another way to make transposing this note easier?

The easiest method in this case would be to lower the G# a half-step to an G. Finding a Major 2nd below G is much easier: it is F natural. Then we raise the F back up a half-step to correct it to F#.

Can we transpose one note at a time?

This is the slowest method of transposing, but it works! Here we are going to move each note down a major 2nd interval to create our transposed melody.

Remember that for each different note we need to count down a 2nd in a different key. Because of this it can be way easier to make mistakes. You will also need to look at your notes to figure out the key signature for your new melody, otherwise you may have a lot of accidentals to read!

What’s next….?

• Learn how to transpose UP a major 2nd
• Learn how to transpose by another interval.
• Learn more about intervals with our complete guide.

FAQs

How can I transpose sheet music up a perfect 5th automatically?

There are a variety of apps that can transpose sheet music such as Sibelius and Musescore.

What about transposing a piece in a minor key Down a major Second?

If you have a piece in a minor key then transposition works much the same. Remember that a minor piece will be transposed into another minor key if we move down a major 2nd. (Similarly a piece with a major key signature will be transposed to another major key).

For example, a piece in A natural minor would be transposed into the key of G minor (two flats- Bb and Eb). This is because A natural is the 2nd note of the G major scale, and so is a major 2nd interval.

In a way it’s easier to think of the original key signature without the major/minor label. If the piece is in A minor, just start with the note A natural and transpose from there. Remember that pieces do NOT change whether they are major or minor by transposing them.

Important- beware of accidentals as these need to be treated independently. Scales such as the harmonic minor and melodic minor use additional accidental outside the key signature.

What is a major 2nd interval?

Remember, when we talk about the notes in the scale we just focus on the letters and not the accidentals.

All of the intervals written below are a 2^nd!

So how do we know what type of interval is a Major 2nd.

As you know from your theory education, our intervals have a descriptive word. We won’t go into this too much today but just as a brief overview, our intervals can be described as major, minor or perfect (there are more descriptions but watch out for more blog posts coming soon to help you to understand intervals further…! This is not necessary for our transposition).

When naming an interval, we always start with the note with the lowest pitch, in this case Bb. If you look at the piano above, Bb is below C. The notes on the piano are lower to the left and higher to the right! 

Below is the scale of Bb Major. 

As the 2nd note of this major scale is C, we know that this is a major 2nd above Bb.

For a more detailed look at this, check out our guide to the interval of 2nds.