Making Music in Scratch

Making music with code

Did you know you can write code that plays a tune? In Scratch, the Music blocks turn your computer into a little band. You tell it which note to play, which drum to hit, and how fast — and it makes real music. By the end of this lesson you will have coded a short song with notes and a beat.

If Scratch is new to you, start with getting started with Scratch and come back here. Music is also a great place to practise loops, so loops and repeats is a helpful companion lesson.

Step 1: Turn on the Music blocks

Like the Pen, the Music blocks are an extension you switch on.

1. Click the Add Extension button in the bottom-left corner of the Scratch screen.
2. Choose Music from the list.

A new pink Music category appears in your blocks palette. The blocks we will use are:

• play note ( ) for ( ) beats — plays one musical note for a length of time.
• play drum ( ) for ( ) beats — plays a percussion sound, like a snare or cymbal.
• rest for ( ) beats — a silence, a musical "gap" with no sound.
• set instrument to ( ) — changes the sound, from piano to guitar to many others.
• set tempo to ( ) — sets how fast the music plays, in beats per minute.

Step 2: Play your first note

Click a sprite and build this tiny script:

when green flag clicked
play note (60) for (0.5) beats

Click the green flag. You hear one note! Two numbers control it:

• The note number (60) is the pitch — how high or low it sounds. A bigger number is a higher note; a smaller number is a lower note. Note 60 is "middle C" on a piano.
• The beats (0.5) is how long the note lasts. A bigger number holds the note longer.

Click the note number and a little keyboard pops up so you can pick notes just by tapping keys. Try note 67 — it sounds higher.

Step 3: Play several notes in a row

Music is notes one after another. Sequencing is just putting steps in order — see sequences: putting steps in order if you want a refresher. Stack a few play note blocks:

when green flag clicked
play note (60) for (0.5) beats
play note (62) for (0.5) beats
play note (64) for (0.5) beats
play note (65) for (0.5) beats
play note (67) for (0.5) beats

Click the green flag. The notes play one after another, climbing higher — that is the start of a musical scale. Scratch always runs the blocks top to bottom, so the order you stack them is the order they play.

Step 4: Add a beat with drums

A tune feels alive with a drum beat. The play drum block makes percussion sounds. Click the drum number to choose one, such as (1) Snare Drum or (2) Bass Drum.

when green flag clicked
repeat 4
  play drum (1) for (0.25) beats
  play drum (2) for (0.25) beats

This repeat 4 loop plays a snare, then a bass drum, four times — a simple "tss-dum, tss-dum" beat. Loops save you from dragging out the same blocks over and over.

Step 5: Control the speed with tempo

Tempo is the speed of the music, measured in beats per minute. Set it once near the top of your script:

when green flag clicked
set tempo to 100
play note (60) for (0.5) beats
play note (62) for (0.5) beats

• A small tempo, like set tempo to 60, plays slowly.
• A big tempo, like set tempo to 180, plays fast.

Try the same notes at tempo 60 and then tempo 160 to hear the difference.

A worked project: code a short tune

Let's put it all together and code the first line of "Twinkle, Twinkle, Little Star". The notes are: C C G G A A G. In Scratch note numbers, that is 60, 60, 67, 67, 69, 69, 67.

Add the Music extension, then build this on a sprite:

when green flag clicked
set instrument to (1)
set tempo to 120
play note (60) for (0.5) beats
play note (60) for (0.5) beats
play note (67) for (0.5) beats
play note (67) for (0.5) beats
play note (69) for (0.5) beats
play note (69) for (0.5) beats
play note (67) for (1) beats

Here is how it works, step by step:

1. set instrument to (1) picks the Piano sound.
2. set tempo to 120 sets a steady, medium speed.
3. The seven play note blocks play in order, top to bottom, giving the familiar "Twin-kle twin-kle lit-tle star" melody.
4. The last note lasts 1 beat instead of 0.5, so the tune ends on a longer "star".

Click the green flag and listen — you have coded a real song!

Try it: make it your own

You can play notes, drums and set the speed. Now compose your own music with these challenges:

• Finish the song: the next line of Twinkle is 65, 65, 64, 64, 62, 62, 60. Add those notes after yours.
• Add a beat under the tune: make a second script on a different sprite with a forever loop of drums, so a beat plays while the melody plays.
• Change the instrument: try set instrument to (4) for an electric guitar or other sounds, and hear how the tune changes.
• Make it interactive: use when [space] key pressed to play a note, so the keyboard becomes an instrument you play live.

If a note sounds wrong, check its number — small changes in the note number change the pitch a lot. Testing and fixing like this is called debugging, and every coder does it. Have fun making music! 🎵