Mozart’s Allegro in B flat Major K3: Piano Tutorial

Howdy! In today’s episode, we’re going to be looking at another Mozart tune from Nannerl’s Music Book – his Allegro in B flat Major, K 3. We’ll get into the backstory, play through the tune so you can hear it, and then discuss some important theory and performance concepts.

Let’s hop to it!

Here is a link to the sheet music. The version I used was by piupianissimo (in the middle).

Allegro in B flat Major: Backstory

Backstory time! This piece, Allegro in B flat major, was written when Mozart was six years old. Awesome and creative as he was, his dad Leopold likely penned the piece down in the notebook, fixing any errors.

It was composed in 1762, and though Mozart is technically considered a Classical period composer, his early works would have been performed on a harpsichord, and as a result they have a Baroque sound to them.

As I mentioned in the very beginning, this piece is from a collection called “Nannerl’s Music Book”. Nannerl was Mozart’s sister, and this book was basically a family collection of tunes – some of them written by Leopold Mozart, some by Wolfgang, and others were copies of popular tunes at the time.

Check out the video to listen to the piece!

Tempo: Allegro

The first thing you probably noticed was how energetic and fast this piece was. If you’re ever unsure how fast you’re supposed to play a piece, look to the title or the top left corner of the piece for guidance – the word “Allegro” literally means “fast”. So when you have the word “Allegro” in the title, you know you’ve got to play at a decent clip!

Theory Basics: Key Signature

Let’s get some of the basic details out of the way. We don’t need to spend time analyzing this key signature, because the title of the song actually gives it away for us. It’s called “Allegro in B flat Major,” which means it’s in the key of B flat major. Very simple.

So when you play this piece, you have two flats to watch out for – Bb and Eb. When you’re in the key of Bb, that’s what your key signature is. Every key on the piano has its own unique key signature – if you miss the flats, this piece is gonna sound bad.

Song Form: Binary or Rounded Binary?

Now let’s look at the song form. We’re going to figure out if it’s in Binary form, Rounded Binary form, or something else entirely. If you have no idea what I’m talking about, check out this video:

What is Binary Form (Or Rounded Binary)?

To start, you can write a big “A” at the start of the piece, to indicate that this is the first section.

Once you hit the repeat lines, it’s a pretty good indicator that you’re moving into a brand new part, so you can label the next section as “B”.

If this was in binary form, there would be an A section, a B section, and then the song would be over. So now we’re going to look and see if the “A” section comes back for a repeat – if it does, we’re looking at a piece in rounded binary.

And if you take a look at bar 20, you can indeed see that the piece is going back to the notes from the very beginning, which means this is rounded binary. I’ll mark this section off with another “A”.

Allegro in B flat Major: Articulation

So let’s look at some of the articulation details. Articulation just means things like slurs and staccatos.

You’ll notice this piece is full of 2-note slurs. That isn’t just random. A lot of piano students tend to ignore slurs and just focus on playing the right notes and rhythm, but these slurs make a big difference to the piece.

A long while ago, we did a video on” target=”_blank”>two-note slurs (check out the link), because it’ll go into a bit more depth than what we’ll do right now – but still, let’s spend a minute working these out.

When you’ve got two-note slurs, and then two notes that aren’t slurred, you want to pay careful attention that you’re actually lifting up your fingers between the slurs to create a “break” in the sound.

The two-note slur has a drop-lift motion. The first note should be a little weightier than the second, as though you’re landing on the note. On the second note, your finger lifts off, so it has a lighter sound.

DROP-lift DROP-lift

It shouldn’t be super dramatic, but playing in this way does add another layer of complexity to playing. Sometimes people look at songs like this and think “easy”, but really, there’s a lot of subtle stuff going on. Without mastering the subtle stuff, it’s difficult to capture subtleties in a Beethoven sonata, for example.


Just a quick note about upbeats. An upbeat, or incomplete measure, is when a piece doesn’t immediately start on beat 1. So when our time signature is 2/4, every bar should equal two beats. But if you look at this very first bar, you’ll notice it doesn’t even come close to adding up to 2 – the first bar is only a half beat.

If you were counting yourself, you would actually begin playing on the half beat RIGHT BEFORE beat 1. You would count:

1 and 2 (and)

Starting that first note on the last (and).


And that concludes our video on Mozart’s Allegro in B flat Major K3. Give it a whirl – as I already mentioned, it’s quite a bit more difficult than it seems at first glance.

Have fun!


Allysia has been teaching piano in Canada for nearly a decade, and has her Grade 10 RCM certificate. She especially enjoys nerding out to music history and theory. When she’s not making videos or teaching, she’s reading, writing, and jamming in a rock band.