NOTE: Pitch Shifting is still considered a "beta" feature. It can be fun to play with, but the algorighm introduces a significant amount of additional latency when it is active, and this is not being properly compensated. This makes it difficult to use pitch shifting when you are trying to synchronize multiple tracks with different amounts of shift, or if you are synchroning Mobius to an external device.
Pitch shift is very similar to Speed Shift except that the pitch is changed without changing the length or tempo of the loop. In all other respects the functions and parameters used to control pitch shifting are almost identical to those for speed shifting.
Pitch shifting may be controlled using these functions and controls.
Pitch Step
Pitch Up
Pitch Down
Pitch Next
Pitch Previous
Pitch Cancel
Pitch Octave
Pitch Bend
15.1 Pitch Functions
15.1.1 Pitch Step
Pitch Step can change the pitch of the loop up or down in semitones. It is a ranged function which means that it is usually bound to a trigger that supports a continuous range of values such as MIDI notes or MIDI continuous controllers. It is almost always bound to a MIDI note from a keyboard so you can change pitch chromatically by playing the keyboard normally. This can make Mobius behave somewhat like a sampler.
See the description of the Speed Step function for more details about how to create ranged function bindings.
The Pitch Shift Restart preset parameter is often set when using a ranged binding of Pitch Step. This will cause the loop to be restarted whenever Pitch Step is executed, similar to the way keyboard samplers behave.
PitchStep may also be used in scripts but it is not ranged. Instead the amount of shift is specified as an argument to the function. See PitchStep in the Mobius Scripting manual for usage examples.
15.1.2 Pitch Up, Pitch Down
This pair of functions simply raises or lowers the pitch by one semitone. You might use these if you want to raise or lower the pitch in successive semitone steps but don't want to create a separate Pitch Step bindings for each step.
15.1.3 Pitch Next, Pitch Previous
This pair of functions changes the pitch in steps defined by the Pitch Sequence parameter. The parameter may be set to a space-delimited list of numbers that represents positive or negative pitch shifts in semitone steps. For example a pitch sequence of "7 12 0" will raise the pitch by a fifth, then by an octave, then return to normal.
The Pitch Next function advances through the pitch sequence from left to right, and the Pitch Previous function advances through the sequence from right to left. You can change direction at any time.
NOTE: The current location in the pitch sequence is not shown in the UI which can make this difficult to use. The location is available in scripts with the
pitchSequenceIndex variable. This variable may also be set to change the sequence index.
15.1.4 Pitch Cancel
Pitch Cancel will remove all forms of semitone and continuous pitch shift being applied to the track. It will cancel the effects of all pitch functions and pitch controls, and reset the Pitch Sequence index back to the beginning.
This can be useful to get things back to normal if you have been combining Pitch Step, Pitch Bend and Pitch Octave in various ways without having to individually cancel each function and return the controls to their center positions.
15.2 Pitch Controls
There are three controls that may be added to the track strips to display and change pitch.
Pitch Controls
15.2.1 Pitch Octave
Pitch Octave is a control that can be used to change the pitch up or down by one or more octaves. The maximum range is 4 octaves up or down. When bound to a MIDI continuous controller, the controller will sweep through a range of 8 octaves. The center value of 64 will result in no shift.
15.2.2 Pitch Step
Pitch Step will appear as both a control and a function in the binding windows. You can achieve similar effects with either target, but main difference is the way in which the binding arguments are handled.
When Pitch Step is bound as a control, the binding arguments must follow the
conventions of Control Binding Arguments which have values such as min, max and center.
When Pitch Step is bound as a function, the binding argument may only have a single integer value which specifies the amount of shift in semitones.
Another difference between the Pitch Step control and function is the range of values. The Pitch Step control range is defined by the Pitch Step Range preset parameter which defaults to 24, meaning two octaves up and down. The Pitch Step function range is defined by the global parameter Speed/Pitch Note Range. Because the control range is defined by a preset parameter, you can design prests with
different ranges if for example you want a control that sweeps over a smaller range of semitones.
15.2.3 Pitch Bend
Pitch Bend is a control that can be used to change the pitch up or down by very fine units resulting in a seemingly smooth or "continuous" pitch change. The effect is similar to using the pitch bend wheel on a keyboard.
Unlike most controls, this one is commonly bound to the MIDI Pitch Bend trigger which has a larger range of values resulting in smoother bends. You may also bind
this to a MIDI continuous controller, but these have less range and may result in a more audible "zipper" sound as you hear the pitch change in small steps.
The internal range of the pitch bend control is defined by the Pitch Bend Range parameter. This defaults to 12 which means one octave up or down.
15.3 Pitch Parameters
Most pitch-related parameters are found under the Effects tab of the preset window.
Pitch Parameters
15.3.1 Pitch Sequence
This is a preset parameter found under the Effects tab. It may be set set to a space-delimited list of numbers that represents positive or negative pitch shifts in semitone increments. For example a pitch of "1" is one semitone above normal, a pitch of "-7"
is 7 semitones below normal (or a perfect fifth lower). Once a pitch sequence has been set, the pitch may be changed using the Pitch Next and Pitch Previous functions.
15.3.2 Pitch Step Range
This parameter defines the range of the Pitch Step control. The default value of 24 means that the range is 24 semitones, or 2 octaves up and down for a total range of 48 semitones. The smallest value is 1 which gives you a range of 2 semitones, one up and one down.
You may wish to lower the step range when binding to a MIDI continuous controller to give you more control when selecting steps. If the range is too high, very slight
changes to the knob or pedal will change pitches. With a lower range, the knob or pedal must move a longer distance before changing pitch.
15.3.3 Pitch Bend Range
This parameter defines the range of the Pitch Bend control. The default value of 12 means that the range is 12 semitones, or 1 octave up and down for a total range of 24 semitones. The smallest value is 1 which gives you a range of 2 semitones, one up and one down.
You may wish to lower the bend range when binding to a MIDI continuous controller to give you a smoother and more subtle bend.
15.3.4 Pitch Shift Restart
When this boolean parameter is true, the current loop will be restarted from the beginning whenever the pitch is changed by the Pitch Up, Pitch Down, Pitch Cancel, Pitch Next, Pitch Previous, and Pitch Step functions.
This is commonly used when doing a ranged MIDI note binding to the Pitch Step function so that Mobius will behave simlilar to a keyboard sampler. Once the loop is recorded, you can play it chromatically on the keyboard, retrigging the loop with each new note.
15.4 Pitch Combinations
You may use all of the pitch functions and controls at the same time. For example if you turn the Pitch Octave control to -1, then turn the Pitch Step control to 12, the effect will be normal pitch since when you add the effects of drop of one octave (-12 semitones) to a rise of 12 semitones, you get 0 semitones. No pitch shift will be heard.
Like Speed Combinations, the pitch shift range is limited to 4 octaves up or down.