RhythmX #1 ( 7 mins)



Let’s take a look at exploring rhythm.  Emuso provides RhythmX, a package of various tools,  specially designed for this.  In essence, a rhythm created by one instrument (or voice) is made up of sounds and silences of varying durations. You can think of this as chopping up time into slots of various durations, which either hold one or more notes (a chord), or silence.  We call each slot an onset.

What you will learn

RhythmX creates, edits, and plays back one or more tracks.  Each track holds one or more parts.  Each part holds one or more bars (see below) for the rhythm (the onsets).  When a track is created, a part can be defined containing some number of empty onsets all the same duration, which can be added to the end of the track (or the empty track). You’ll explore creating tracks and parts later.  Over the series of RhythmX quick starts, there are exercises where you’ll ultimately have created an 8-bar ballad, with chords, melody, bass, and drums as you learn RhythmX.  You’ll save each exercise for use in the next quick start.

In this quickstart, you will “refining”  parts we have already defined, to create a chord progression.  You will learn about this “part refinement” which is used to change the number of onsets and their duration, and to place notes into onsets.  Then you will practice using the “Refine part” tool, which carries out these changes, and briefly look at switching between the set of RhythmX tools..

By the end of this post, you’ll know how to create a tune with chords, play it back, and save it.  We’ve pre-prepared a snappet which has one track, with one part, for you to use in the exercise below.  You’ll transfer notes from the emuso “guitar”, into one  or more onsets in a part.   For this, you’ll use “Refine Part” (one of RhythmX’s tools). In particular, you’ll familiarise yourself with its playback controls and the buttons “Chord“,  “Join left“,  “Chop onset“, and “Rest/clear”

First let’s take a very quick look at a couple of rhythmic concepts, beats and bars.

Each of the following sections can be expanded by clicking on its heading, and collapsed by clicking on the heading again.


Beats and bars

With almost all music, you become aware of regularly occurring points of time, due to when sounds start, and their durations.  If you are dancing, you synchronise your movements with the points, even if there is no sound at that point.  What’s more, you repeatedly become more aware of  one time point in a group of time points, such as ONE two three four  ONE two three four. This is because the sounds are so well organised with where they start in time, and their duration.  What you are sensing is the beat, where sounds often start (though not always). Written down, music is organised into bars, for example, 4 beats in the bar, where each bar holds what ever music is occupying that group of beats, and a vertical line separates bars.  Different symbols denote the duration of a note, written down.

Below are three tracks of music in Rhythm-X, “gtr-chords”, “bass drum”, and “snare”. We can see the first four bars of each track (numbered 1 to 4), and the beginning of the fifth bar.  Each bar occupies the same width.  Each numbered vertical line indicates the start of a bar.  In the empty space below these tracks, all the vertical lines are evenly spaced apart, and each denotes the start of a beat.  Here, these lines show there are four beats to the bar.  In a track, a bar may be broken up into different width rectangles, indicating the onset of a note and its duration.  For example, the first bar of the snare track is broken into four, each onset coinciding with a beat.  Only the third onset is producing a sound (as shown by the solid ornage circle there), while the others are currently empty. (Click on the image to enlarge it)


Part refinement

When a track is created, it holds no parts.  When a part is added to a track, that part contains empty onsets of equal duration.  The actual number depends on how the part is defined.  The reason for this is that very often one or more bars of a melody mostly use one particular duration.  You then edit this rhythm as needed, to shorten or lengthen some notes and so on.  We’ll look at editing now, and you’ll learn about defining a part in the RhythmX #2, when you will create a bass drum track and a bass track..

Part refinement is the action of adding note(s) from a virtual instrument to empty onsets, replacing the content of onsets, changing the duration of onsets, by chopping them up or joining them together, and emptying out onsets. The onsets in the part can also be “time displaced”, but that will be covered later.


Refine Part Tool

Here is an picture of RhythmX, loaded with a snappet you’ll be using for this exploration. Click this picture to enlarge it (switch to full-screen if necessary to see this properly).


There is one track, with one part, showing as one row on a grid. Notice there are eight rectangles in the part. These rectangles represent onsets. The width represents the duration. During playback, each onset is played for its duration (there may be no sound, if muted or empty) one after the other.

To the left of the track, there are two buttons. One is labelled with the track name (e.g. “gtr chords”), and is used to change its sound properties (the volume, pan, and MIDI instrument for the track). The other button “Define part” is used to define a new part and append it to the corresponding track. You’ll learn about these in RhythmX #2.

Above the track grid are the playback controls (at the left) and the “Refine part” tool is on the right. You’ll try some of its actions next.

Playback and Metronome Controls

First off, let’s check out the playback controls…

Images of the individual playback control icons are shown here. They aren’t interactive. In use, if an icon appears dimmed, it is disabled.

When clicked in Rhythm-X, this starts playback from the beginning. It becomes disabled when playback starts.

During playback, this is enabled, and the above control is disabled, as is the one shown below. It pauses playback when clicked in Rhythm-X.

When playback is paused, when clicked in Rhythm-X playback resumes from where it was paused.



The image of the metronome icon is shown here. The image isn’t interactive. In use, if it appears dimmed, it is disabled.

When clicked in Rhythm-X, the metronome widget appears.

Trying out the playback and metronome controls

Click the “ear-eye” icon. Follow the instructions below.

Emuso creates a split-screen. This quick start guide is on the left, and the interactive “guitar” on the right, with RhythmX below it, and its “Refine part” tool is showing on the right of the playback controls. (This tool is one of several in Rhythm-X). You may have to drag the split-screen to the left to see more of Rhythm-X. The top horizontal border of RhythmX can also be dragged vertically. Try it.

Underneath the row of four icons is a box labelled “use click”.

  1. Click the “use click” box to ask for a metronome click when you hit play.
  2. Hit the play button. The pause button acitvates. You’ll hear a simple metronome click.
  3. Hit the “pause” button, and click “use click” to turn off the click.
  4. Change the tempo (the number of beats per minute) by typing a value into the box next to the label “set bpm” and press enter or move the mouse out of the box.  The tempo resets to 80 if the final value is smaller than 30 or larger than 300.



Now let’s add some chords.






Click the “ear-eye” icon to show the “Refine part” tool

  1. Click the image above labelled Fmaj7.  This renders the chord shape onto the fretboard.
  2. Let’s transfer this chord to the “gtr chords” part.  Click the “Chord” button in the Refine Part tool.  It turns pale grey, showing it is active.
  3. Click on the first, third, and fifth onset from the left.  Notice these each show a solid blue circle, showing they contain chords.  (These can be inspected in various ways, but that’s for later). If you make a mistake, type “CTL-z” to undo it.
  4. Click the image above labelled A-7 to load it onto the “guitar”. This replaces the previous chord on the guitar.”Chord” is still active.
  5. Click on the second, fourth, and sixth onset from the left.
  6. Click the image labelled G/A
  7. Click on the seventh onset.
  8. Click on the image labelled Bb/C.
  9. Click on the eighth (last) onset.
  10. Start playback.  The Refine part controls become disabled.  Change the tempo to suit you.

It loops until you stop it.  The controls re-enable, with none active.


Watching the chord progression

Click the “Back” button at the right of the playback controls. You’ll see this … the main toolbar for RhythmX.

  1. Click on the button “Choose” in the visual feedback area.
  2. Click on “Link track to active layer“.
  3. Click anywhere on the part you just put chords in.
  4. Start playback if needed. The chords appear on the guitar. Notice that many controls become disabled.
  5. Stop playback.
  6. Click “Refine Part(s)”

Editing the rhythm

You can join adjacent onsets together, with “Join left” and “Join right”. The “Chop onset” commands let you chop an onset into two, maybe unequal durations, or into two or more equal duration onsets, in all cases replicating the original onset’s content in each of the onsets replacing it. The “Rest/clear” commands let you clear out an onset’s contents, and place a rest into an onset (including splitting it first).

Note that a command like “clear onset” remains activated until you choose another one, or start playback, which deactivates the current command, and disables all the other Refine part commands until playback stops. The commands are then reenabled, but none are active.

During playback, the Refine part controls are disabled. Stop playback if necessary, to enable editing.

You’re going to edit the rhythm of the gtr chords part, to give it some “syncopation”,  so some of the chords stand out more to the listener.  For this, you’ll use the “split onset” command.  Directions are below.

The final result in bar 7 and 8 should look like this… click on it (switch to lesson fullscreen first) to make it bigger.  The chord that started at bar 8 has had its onset changed to start a little earlier.

  1. Drag the slider button on the short horizontal slider at the bottom right of RhythmX to the right, to zoom in. The longer horizontal slider can be used to adjust which part of the track to see. You want to see the last two (smaller) onsets in bar 1 of the bass drum track. Notice the horizontal position where the last of these onsets starts.
  2. Click on “Chop onset” drop down and choose “Split onset“.
  3. Click on the chord in the “gtr chords” track at this horizontal position. You now have two onsets each with a copy of this chord.
  4. Click on “Join left” and click on the chord at the start of bar 2. Now, the chord that started in bar 2 starts near the end of bar 1, consuming the additional onset that appeared in bar 1 from the previous step.
  5. Drag the longer horizontal slider so you can see bars 7 and 8. Notice the last two (smaller) onsets in bar 7 of the bass drum track. Notice the horizontal position where the last of these begins.
  6. Click on “Chop onset” drop down and choose “Split onset”
  7. Click on the chord in the “gtr chords” track at this horizontal position. You now have two onsets each with a copy of this chord.
  8. Click on “Join left” and click on the chord at the start of bar 8. Now, the chord that started at bar 8 starts near the end of bar 7, consuming the additional onset that appeared in bar 7 from the previous step.


Listen to your work.

Now clear out the last chord in the progression…

  1. Click on “Rest/clear” and select “Clear onset”.
  2. Click on the last chord (bar 8)
  3. Have a listen
  4. Type “Ctl-Z” to bring back the chord.


Saving your work

Use the File menu at the top left of emuso, and select “Save snappet”. Choose where to save it on your machine. In the next quick start guide, you can either continue with this, or work with a snappet we’ve provided, to add melody to the “gtr melody” part.


What you have learned

You’ve learned the RhythmX provides tools for exploring rhythm. You learned that rhythm can be thought of as slices of time, some of which hold notes. We call these slices “onsets”. RhythmX deals with tracks. each track has one or more parts, and each part has one or more onsets. You’ve learned that part refinement is the action of adding note(s) from a virtual instrument to empty onsets, replacing the content of onsets, changing the duration of onsets, by chopping them up or joining them together, and emptying out onsets. You learned how to use some of the controls in Refine part: “Chord”, “Join”, “Chop onset”, “Rest/clear”. You also learned using “Back” on the “Refine Part” toolbar to get to the Main toolbar, and using “Refine Part” on the Main toolbar to get back to “Refine Part”.


You carry on from where you left off now. In the next quick start, you learn how to add tracks for a bass part, a guitar melody part, and a hi-hat percussion part. You’ll also learn how to change the sound for each track (MIDI instrument, volume, pan, MIDI driver), and how to (un)mute tracks, part, or individual notes. You’ll also learn how to (un)stress individual notes.