Theory quick start (4 minutes).



This guide won’t cover theory per-se. Interactive content instead presents theory (such as our blog content). This guide covers what support is built into emuso for visually reminding you of intervals, for discovering relationships between chords and scales, chords and chords, and scales and scales, using mouse interactions on-“instrument”, using the “clock instrument” and using the “Rel-X” tool.

What you will learn

First, you’ll learn about intervals. Notes (circles) on instrument can display interval information, or note names. A colour scheme is used to denote the interval, by colouring the rim of the note’s circle. You’ll learn about these next. You’ll learn how to set up your own colour scheme. Then you’ll learn about mouse interaction to generate a chord or pentatonic by hovering over a scale note with the ALT key held down. Then you’ll learn how to use the clock-instrument, which effectively collapses all notes on instrument onto clock times 0 AM to 11 AM, and finally you’ll learn how to use Rel-X

Intervals and how we experience music

Intervals are foundational to music theory.  An interval consists of just two notes (played on the same or different instruments).  The number of semitones apart these two notes are determines the sound flavour we hear.  (If needed, check out Introducing pitch, octave, semitones).  Scales, chords, melodies all consist of intervals.

The way we experience music is by hearing one or more intervals interacting to produce a range of sounds, from stable, to clashy, demanding change to come along to remove the clashing. Where these occur in the rhythm makes a big difference, as does how fast the notes creating these intervals are played.  The rhythm usually contains a mix of silence and a stream of notes, then more silence, and so on.  Our brains are very aware of the change from silence to music and vice-versa, so the first and last notes stand out more.  Notes in the middle of the music, and especially those on the off-beat, don’t stand out (unless there’s a big change in the register of the note from its surrounding notes).  This means we can slip in notes that clash with the other instruments are playing, as some ear candy, briefly heard and then gone.  In other words, you can play any note against any chord, so long as any clashes are dealt with, replacing it with a nearby non-clashing note (unless you wany to increase the expectations of the audience by not doing this).  Just don’t end a stream of notes with a clash.

De-prioritising note names makes a huge difference

Placing primary importance on intervals, as opposed to note names drastically reduces what you have to remember about scales and chords, about important notes in these, and about chords found within chords, and scales found within scales. Learning intervals as early as possible is critical to solid and rapid progress learning the guitar.

Interval primer

This next interaction creates a block of 16 notes along the bass E string (6th string), starting at the anchor located at fret zero.

  1. Notice the notes are labelled 0 to 15 starting at the anchor at fret 0, as these notes are various semitones ABOVE the anchor note. The absolute semitone distance from the anchor to the note is shown in the label. Adjacent frets on the same string produce notes that are a semitone apart.
  2. Click”Reroot” on the interval and pitch strip. Left click on the note at fret 12 on the bass string. This note is now the anchor. Interval distances are now measured from the anchor here.
  3. Notice the labelling is now showing negative values below fret 12, as these notes are various semitones LOWER than the anchor note
  4. Click “Toolkit” and click on the “Octave” button. Dim red circles appear at all octaves of the anchor.
  5. CTL-left click on each of these dim red circles, to relocate the anchor. Since this is a scale fragment laid out along one string, some of the fragment may “fall-off” the string. Notice the labelling each time.
  6. Click “Toolkit” to turn it off. The scale fragment present on entry to the Toolkit is restored.

When improvising, we never think of semitones above or below. This next interaction shows a different form of labelling … “semitone distance from the nearest lower octave of the anchor“. When improvising, we want to be aware of this, though in a slightly different form (“location of interval symbol from the nearest lower octave of the anchor“) coming up shortly.

Make sure you have exited the Toolkit before you try this.

  1. Notice the labelling is now showing values in the range 0 to 11, showing the semitone distance from the nearest lower octave of the anchor (12 semitones lower). This is visually obvious if you look at frets 11,12 and 13. In other words, we can identify a particular note within an octave of the nearest lower anchor, such as “3”, being the 3rd semitone above the start of that octave.
  2. Click “Reroot” and left-click on the 9th fret of the 3rd string. The anchor is now there, The labelling is unaffected.
  3. Left click on the 9th fret and the 10th fret of the 3rd string, creating notes there, including a note at the anchor at the 9th fret.
  4. Left-drag the anchor and watch what happens. The labelling is always relative to the anchor.
  5. Left-drag the anchor towards the bass string, and observe how the scale fragment “falls off”, and reappers when you Left-drag the anchor towards the treble string.
  6. Type “i” (lower case) three times, until you see labels like “b3”, “b5” appear on the notes. “b3” is the theoretical symbol for a note 3 semitones above the nearest lower anchor. “b5” equates to a note 6 semiones above the nearest lower anchor.
  7. Left-drag the anchor again. Observe how the same symbols appear relative to the nearest lower anchor.

Now let’s look at a scale. You’ll be asked to select all the “b3″s that you can see.

You can choose how you want notes to be labelled on-instrument. At a minimum, the note can be set to black with a white rim (no information).

Emuso uses a colour-scheme to denote different intervals. The note can appear black with coloured rims (a slight reminder of the intervals). Additional information can be presented withing the note’s circle.

  • semitones
  • absolute semitones
  • interval symbols per octave
  • note names

You can switch between these, repeatedly pressing “i” (make sure the mouse is in the same pane as the instrument). The labelling you need to become familiar with is “interval symbols per octave”, as you practice learning scales and chords.

You can also use “=” to switch between semitones in the range 0 – 11. and interval symbols per octave.

For example, here you will see how the same interval “b3” occurs both in the scale and a chord found in that scale. Knowing this, yo can think “I’ll land on the b3 when improvising with this scale over this chord”. After a while, you just know this is a good landing note without especially thinking it’s a b3. But, during directed practice, you absolutely must recognise it is a “b3”, for example.

Chord and Scale theory reimagined

Theory details what intervals make up a chord or a scale. This can be visualised using emuso’s clock-instrument, independently of musical instrument, to understand the intervals involved. You effectively look at one or more octaves of pitches, all collapsed onto the the twelve hours (0 AM to 11 AM) of the clock face. Replicating these intervals on a musical instrument involves selecting these intervals from the anchor, and placing them in various octaves … this is what you need to know for performance, and what emuso’s chord and scale libraries do for you. But this is a lot more detail than required to understand the note relatonships between chords and scales, chords and chords, and scales and scales.

Let’s take a look…

Now let’s have a look at the Rel-X tool.

  1. Press “Toolkit”, click “Scale” and select “Mixolydian”.
  2. Click button “Large clock…” near top right of emuso.
  3. Now we’re going to look for anuy major chords that exist in this scale …
  4. Click “Rel-X” at the top right of the large clock.
  5. Click on the dropdown arrow next to the button labelled “by marker click”
  6. Choose “from Chord menu”. Notice the button changes color to orange, as does the Chord button in the Toolkit, to remind you that any chords will be sent to Rel-X, and not the instrument.
  7. Click on the Chord button in the Toolkit and select “sus 4”. (The “sus 4” chord is made up of interval symbols 1, 4, and 5, or semitones 0, 5 and 7)
  8. Type “=” so the labelling changes to semitones in range 0 – 11.
  9. Notice the spokes at times 0, 5 and 7 have all lit up orange. This shows the intervals for the chord are found if the chord is built starting at the scale start note (0 AM).
  10. Click “Rotate+” on Rel-X. The spokes rotate by one position. None light up orange. The scale does not have the right intervals to build a sus4 chord there.
  11. Click “Rotate+” again. The spokes rotate so the chord root aligns with the second note of the scale (at 2 AM). The spokes light up. We have a match.
  12. Keep rotating. You’ll find another match at 5 AM.
  13. You’ve found that the sus 4 chord can be built rooted at the scale pitches located at 0, 2 and 5 semitones above the scale start note.

Now let’s look for a scale called “major pentatonic” (its semitone intervals are 0 2 4 7 and 9).

  1. Click on the dropdown arrow next to the button labelled “by marker click”
  2. Choose “from Scale menu”. Notice the button changes color to orange, as does the Scale button in the Toolkit, to remind you that any scales will be sent to Rel-X, and not the instrument.
  3. Click on the Scale button in the Toolkit, scroll down, and select “Major Pentatonic”. (This has semitone intervals 0 2 4 7 and 9)
  4. Notice that the spokes at times 0 2 4 7 and 9 all light up orange. So, the mixolydian scale contains this pentatonic, starting at the first note of the mixolydian scale.
  5. Keep rotating, and you will find matches at times 5 and 10 as well. The pentatonic can be built from the mixolydian scale pitches located at times 0, 5 and 10.

Scales that are “roughly” right for a chord are often used for aural effect. Rel-X can be used for this, and also to find chords within chords.