Chapter 9. Pattern Editor

Table of Contents

9.1. General
9.1.1. Note Types
9.1.2. Controls
9.1.3. Sidebar
9.2. Drum Pattern Editor
9.3. Note Properties Editor
9.4. Piano Roll Editor

Figure 9.1. Pattern Editor in Drum Mode

Pattern Editor in Drum Mode

This is where it all happens, this is where you can make music :-)

The Pattern Editor allows you to create and modify the pattern selected in the Sidebar of the Song Editor by adding/removing notes and tuning a number of per-note properties, like velocity and pan. The Pattern Editor can be used in two modes: as Drumkit Editor or as Piano Roll Editor. You can switch between these two by clicking the Grey button containing a small piano illustration with three white and two black keys. and Blue button with a quasi-3D display a cylinder with black outlines, blue sides, and a white top. button (located on the top-right of the Pattern Editor).


If you are editing a pattern in Selected Pattern Mode you will always hear the pattern you are editing when you playback is rolling.

If you are working in Stacked Pattern Mode you will hear the active pattern(s), not necessarily the pattern you are currently editing.

9.1. General

9.1.1. Note Types

Four notes are displayed in one line of the Pattern Editor. The one to the left is rendered as black circle. The one right of it consistents of an identical black circle as well as a black triangle expands over two grid cells. The third one is a a semi-transparent circle and the right-most one is rendered as a blue circle.

There are a couple of different notes you can create and encounter within the Pattern Editor. From left to right: regular, custom length, inaccessible, and stop-note.

  • Solid black circle. : Regular note (or just note) can be created using left-clicking or Enter.

    Triggers playback of a whole sample of the associated instrument.


    The inner color of the circle represents the note's velocity. Black: 80%, red: 100%, blue: 50%, white: 0%. But in contrast to a stop-note these circles do always have a black outline.

  • Solid black circle extended to the right by a rectangle of the same color. : Custom length note can be set by right-click dragging a regular note.

    Similar to a regular note but only plays back the sample until the specified point. Afterwards the Release of the instrument kicks in to cut off the sample gracefully (small values) or to add a fade out (larger values).


    The length of the note is specified in ticks and changes along with the tempo. The sample, however, consists of a certain amount of audio frames and will not change with tempo (unless you activated Rubberband).

  • Semi-transparent black circle. : Inaccessible note

    A regular note which is not part of the pattern you are currently editing. Instead, it belongs to a different one currently played as well. This could be within the same column in Song Mode while the Pattern Editor is locked, activated in Stacked Pattern Mode, or as part of a Virtual Pattern.

  • Solid blue circle. : Stop-note can be created using Shift + left-clicking

    Stops rendering of all notes associated to the corresponding instrument. Afterwards the Release of the instrument kicks in to cut off the samples gracefully (small values) or to add fade outs (larger values).

9.1.2. Controls

Figure 9.2. Pattern Editor Controls

Pattern Editor Controls

The top part of the Pattern Editor contains a number of controls applying to both the Drumkit Editor and the Piano Roll Editor:

  • Two blue combo boxes showing "4.00" and "4" and are labeled "Size". : lets you choose the length of the pattern (in note values).

    The left combo box represents the numerator of your current measure. You can enter a decimal numerator, like 4.5/4, but since resolution in Hydrogen is limited, some values are not supported and can not be entered.


    Hydrogen supports (only) the following denominators (right combo box): 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, and 192 because these are the factors of the maximum resolution (192 ticks per whole note).


    Typing / within the numerator (first combo box) also you to quickly jump to the denominator.

  • Blue display showing "1/16" and titled "RES". : this is the current grid resolution (1/4 through 1/64 with triplet-based resolutions marked as 1/8T).


    If you are working with a resolution of 1/16 you can't go back to 1/8 and remove an upbeat 16th note by clicking it. But you can still select and remove it via dragging or keyboard.

  • Blue button containing a black speaker symbol. : when checked Hydrogen will play back notes as they are being added to the pattern (even if transport is not rolling).


    When disabled you will still hear the preview sound when clicking on the instrument name in the Sidebar. Be sure to click at the left-most position - where the preview is silent - in case you don't want to get disturbed. Or switch the currently selected instrument using and .

  • Blue button showing a black 2 by 3 grid. : enables/disables quantization. When checked, notes recorded using incoming MIDI messages or Hydrogen's Virtual Keyboard will automatically respect the grid resolution currently applied, just like notes inserted by clicking.

  • Grey button containing a small piano illustration with three white and two black keys. / Blue button with a quasi-3D display a cylinder with black outlines, blue sides, and a white top. : switches between Drumkit Editor and Piano Roll Editor.

9.1.3. Sidebar

Figure 9.3. The Sidebar of the Pattern Editor

The Sidebar of the Pattern Editor

The section on the left shows you which drumkit was loaded last and below that you can see the instruments that are part of the current song.


Keep in mind that these are not necessarily the instruments of the kit associated with the displayed name! Each song has its own set of instruments.

Left-clicking the box containing the instrument name will play back a sample of the instrument. Which layer will be select depends on the horizontal position of the mouse click representing zero velocity to the left and maximum velocity to the right. In addition, each instrument has its own set of features that are accessible by right-clicking the instrument. From the context menu that pops up you can select.

  • Delete notes: removes all notes for this instrument in this pattern.

  • Fill notes: this allows you to fill up the pattern with notes for the selected instrument.


    Depending on the choice you make (fill all, fill 1/2, fill 1/4 ...) notes will be placed at all, 1/2, 1/4, etc of the note positions that are allowed by the grid setting. So be careful not to mix up the 'musical' 1/2-note and the 'fill 1/2' note.

  • Randomize velocity: automatically apply a pseudo-random velocity to each note of that instrument in the pattern.


    The more velocity you set on the instrument, the more Hydrogen will hit hard on that instrument when played.

  • Select notes: will select all the notes played on this instrument in the current pattern. They can then be copied, moved etc. in the Pattern Editor main area.

  • Edit all patterns: this section of the menu has actions which operate on notes played by the instrument in all the patterns of the song.

    • Cut notes: remove all notes played on this instrument, in all patterns, and keep them in the clipboard.

    • Copy notes: copy all notes played on this instrument, in all patterns, to the clipboard.

    • Paste notes : paste a multi-pattern selection from the clipboard to this instrument.

    • Delete notes: delete all the notes associated with this instrument, without affecting the clipboard.


    These can be used together to change the instrumentation of a song, entirely replacing one instrument with another by just copy and pasting the notes to a new instrument.

  • Instrument: this section of the menu has actions which operate on the instrument as a whole:

    • Rename instrument: change the name of the instrument.

    • Delete Instrument: well, deletes the instrument ;-)

The Grey button containing a black "M". button mutes the instrument and Grey button containing a black "S". solos it.

The order of the instruments can be rearranged by simply dragging an instrument up/down in the list and dropping it on a new position within the drumkit. Doing so will not change the sequence of notes you have created for that instrument, nor will it change anything about the song or pattern you are working on.


It will, however, have an impact on the MIDI note mapping.


Rearranging the instruments will also mess up the per-instrument JACK output ports. Be sure to have your drumkit set up before starting wiring.