These are intervals of 3, 4, and 7 semitones.

To create an interval of 3 (or 4 or 7) semitones, choose any note, and play the other note 3 (or 4 or 7) semitones higher.

Try it:

A chord is a sound made up of three or more notes.

You can choose any three or more notes you like from the major scale, and get some sort of chord. But some sound better than others.

Here’s the major scale again …

Try this. Hold down the ALT- key (Opt- key on Mac) and hover (no press or click) the mouse over label 0. ? Then label 2. Label 2 is 2 semitones above label 0. Then back. Emuso generates chords starting at (we say “rooted at“) each of these labels. Try listening to them both melodically and harmonically,using the Play Style tool.

The label is effectively locating one of the scale notes (thus forming an interval with the start note, labelled 0, of the scale).

We can think of intervals at two levels:

• Level 1:? the inteval from the scale start note (0) to any scale note.
• Level 2: the interval from any scale note to other scale notes.

When talking about chords, level 2 is the interval from (a chord rooted at) some scale note to other scale notes making up the chord.

Informally, emuso is applying the “choose-skip” method to choose the notes your heard above. This works as follows:

1/ Choose a starting labelled note (this is equivalent to the label you hovered over)
2/ Skip over the next labelled note
3/ Choose the next labelled note
Repeat 2/ and 3/ until you have chosen all the notes you want. Above, emuso chose 3 notes.

Try the ALT-key again, and this time notice which labels (notes) are chosen, and which are missed out.

Here’s the really important concept

If we shift the blocks, as we did above, then the notes involved, the piano keys used for the scale, change. But, as choose-skip works relative to some label, the resulting chords all involve the same labels. We get the same chord types, the same sound flavours, just higher or lower. This is great news, as it means there is far less to remember compared with remembering the note names involved.

To drive this point home, drag the left-most label 0 as far to to the left. Use ALT- and hover over label 0. Labels 0, 4, and 7 swell up. Release the ALT-key and move the mouse over each of these labels, and write down the note names that swell up below the piano. You should have written down C E G.

Now drag the left-most label 0 right by 1 piano keys. Use ALT- as above. The same labels as before swell up. We have the same chord type as these distance are maintained. Release the ALT-key and move over each of these labels 0, 4, and 7. Write down theoir names. You should have written down C# E# G#. Don’t worry about these names, they really aren’t important at the moment.

Imagine repeating this procedure at all the 12 possible block positions. You’d have written down 12 different sets of note names. And that’s just for the chord starting at label 0. Do the same for labels 2 4 5 7 9 and 11, and you’d have written down 84 (7 x 12) sets of names!? But we’re not done reducing what we need to remember…

When you use ALT- hovering over label 0, labels 0, 4, and 7 swell up. We can think of these labels as indicating a distance (number of piano keys) from label 0. This is easier to see if you set Play Construct to Harmonic and remain over label 0 for awhile.

We refer to their notes as a triad, and the notes involved are found at 0, 4, and 7 piano keys above (to the right of) the piano key for label 0. We call this set of distances a major triad. If someone says “major triad”, think 0, 4, and 7.

When you use ALT- hovering over label 2, labels 2, 5, and 9 swell up. We can think of these labels as indicating a distance (number of piano keys) from label 2.

What’s the distance (number of piano leys) from label 2 to label 5? That’s 3, right? (5 – 2)? ? And from label 2 to label 9? ? That’s 7.

Measuring from label 2, we have distances 0, 3, and 7. ? We call this set of distances a minor triad. If someone says “minor triad”, think 0, 3, and 7.

With this in mind, ALT-hover over label 5. Write down the distances from there to each of the swollen labels. What about from label 7? What we we call each of these sets of distances? Major triad or minor triad?

Do the same ALT-hovering over label 4 and label 9. Do we get major or minor triads?

To check you answers, see the section “Major scale triads”.

The same way scale are movable, so are chords. While they originate from scales, we can create them anywhere on the piano by choosing where 0 is located, and then using the major or minor triad distances to locate the other members of the chord. They keep their sound flavour, just higher or lower, same as scales do.

Try this. You will moving around major and minor triads.

We can also repeat or move any of the required notes, to get a fuller sound for the chord, without changing its basic sound flavour.

Major scale hosts

• major triads at labels 0, 5, and 7
• minor triads at labels 2, 4, and 9
• A different triad is hosted at label 11, but it’s uncommon, so we’ll ignore that for now.

Finally, emuso handles automatic chord generation for the last scale that has been created. Lets look at this.

First, lets create the major scale again.

1. Click “Toolkit” (top left of emuso)
2. Click “Chord-X”. The major scale now appears across the piano.
3. CTL+ Click on any of the labels 0, 5, or 7, and a major triad is created.
4. CTL+ Click on any of the labels 2, 4, 9, and a minor triad is created.

So you can experiment with some chord progressions from the major scale. For example,

1. CTL+ Click 0, 5, 7, 5, 0
2. CTL+ Click 0, 2, 4, 5, 5, 4, 2, 0
3. CTL+ Click 0, 9, 2, 7, 0

Have fun!