• Importing from a MIDI file

The Sequencer module provides a powerful step-based modulator that synchronizes with the host tempo and can be programmed with patterns of up to 128 steps. In addition to the level of each step, its groove/shuffle and its envelope can be controlled, both globally for the whole pattern and locally per step.

(Click to view full size.)

The step editor at the right-hand side of the Sequencer module is fairly self-explanatory. Steps are numbered from left to right across the top of the display. In the usual Values mode, the value of each step is represented by a vertical bar (or by a totally empty column when the value is zero).

• Drag a bar up or down to adjust its value, or click directly at the desired height.
• Set the values of multiple bars by simply dragging left or right across them.
• Right-click (or control-click) a bar to set it to zero.
• You can ‘tie’ one step to the next by shift-clicking below it. A small ‘chain-link’ symbol appears below each tied step. When two or more steps are tied together, they behave like one longer step.

The step editor can be switched to two additional modes besides the usual Values mode. In Length mode, you can edit the step lengths to create a pattern of longer and shorter envelope shapes (so that the attack, sustain, and release stages fill a larger or smaller portion of the fixed step duration). These lengths are combined with the Sequencer’s overall Attack/Sustain/Release settings to determine the envelope shape of each step. In the following illustration, Step B has a greater value than Step A, but Step A has a greater length than Step B.

When the step editor is in Swing mode, finally, you can create variations in the timing of the steps. Each swing value ranges from 0 to 2; the middle value of 1 represents normal timing, while smaller values play earlier and larger values play later than normal. These swing values are combined with the overall timing pattern determined by the Sequencer Shuffle control.

The remaining Sequencer controls are as follows:

• FILE button — click to access a pop-up menu with the following commands:
  • Save stores the current Sequencer configuration (step values, lengths, and swing settings; plus the settings of the remaining Sequencer controls) in a new disk file (*.seq), while Load applies the configuration stored in an existing disk file.
  • Copy stores the current Sequencer configuration on the clipboard, and Paste applies the configuration currently found on the clipboard.
  • Clear resets the Sequencer controls and pattern to their default settings.
  • Randomize applies random offsets to the Shuffle, Attack, Sustain, and Release settings (described below).
  • The Import functions are described in a separate section below.
• Current Sequencer field — Alchemy provides up to 16 Sequencers, and if you are working with a preset that uses more than one, you can access each Sequencer’s control panel by selecting its number in the Current Sequencer field.
• TRIGGER button — When TRIGGER is activated (lit) the sequencer pattern plays from the beginning with each MIDI note-on. With TRIGGER deactivated (unlit), the Sequencer runs continuously.

Note that the Sequencer module always play in sync with the host tempo, regardless of the TRIGGER setting.

• Duration determines the duration of each and every step in the pattern, expressed as a fraction of a beat. (Assuming a quarter-note beat, ‘1/2’ produces eighth note steps and ‘1/4’ produces sixteenth note steps.)
• Steps determines the length of the Sequencer pattern (number of steps, from 1 to 128)
• Snap quantizes the step values, limiting them to exact fractions of the available range. For instance, a Snap setting of ‘1/2’ means that bars will snap to the values 0%, 50%, and 100% when dragged. A Snap setting of ‘None’ turns quantization off and allows you to set step values freely.

Note that the Snap setting does not move existing step values into alignment with quantized positions; it only affects how step values respond when you move them by clicking and dragging in the step editor.

• Shuffle lets you create various ‘swing’ effects. Setting a Shuffle value greater than 0% increases the duration of the odd-numbered steps (1, 3, 5, …) and decreases the length of the even-numbered steps correspondingly.
• Attack determines the amount of time each step takes to reach its peak level.
• Sustain determines the amount of time each step is held at its peak level.
• Release determines the amount of time each step takes to fall from its peak level.

Importing from a MIDI file

Alchemy is capable of extracting information from a short MIDI file and applying it to patterns in the step editor. Specifically:

• It can extract velocity data and set the step values to match. If the MIDI file consists of notes of equal duration (e.g. a succession of eighth notes, or a succession of sixteenth notes), then every step in the resulting pattern will have an associated non-zero value. If the MIDI file consists mainly of notes of equal duration with occasional gaps (e.g. a succession of eighth notes with occasional eighth rests), then the gaps will be represented by step values of zero. If the MIDI file has more irregular timing, or if it consists of chords rather than single notes, then the results of this process will be less predictable and usually less useful.
• It can extract groove data (timing inflections) and set the step swing values to match. If the MIDI file consists of nearly equal durations (e.g. eighth notes or sixteenth notes with timing inflections), this process yields meaningful results.
• It can extract note data (pitches) and set the step values to match. The MIDI file should consist of equal durations with no gaps, and it should be limited to single pitches between a low C and a C two octaves higher (e.g. C1 through C3); the low C corresponds to a step value of zero. (Because the pitch range is always two octaves, which is equivalent to 24 semitones, you should use the sequencer to modulate pitch with a depth of 24 semitones in order to reproduce the pattern of notes in the original MIDI file.)

Three import commands in the Sequencer FILE pop-up menu make use of these capabilities.

• Import Velocity — sets step values based on extracted velocity data and swing values based on extracted groove data.
• Import Note — sets step values based on extracted note data and swing values based on extracted groove data.
• Import Groove — sets swing values based on extracted groove data.