# Pitch shift

amp: | 1 | mix: | 1 | pre_mix: | 1 | pre_amp: | 1
window_size: | 0.2 | pitch: | 0 | pitch_dis: | 0.0 | time_dis: | 0.0

``

    with_fx :pitch_shift do
      play 50
    end

Changes the pitch of a signal without affecting tempo. Does this mainly through the pitch parameter which takes a midi number to transpose by. You can also play with the other params to produce some interesting textures and sounds.

Introduced in v2.5

## Options

amp: | The amplitude of the sound. Typically a value between 0 and 1. Higher amplitudes may be used, but won’t make the sound louder, they will just reduce the quality of all the sounds currently being played (due to compression.) Default: 1 Must be zero or greater May be changed whilst playing Has slide options to shape changes
mix: | The amount (percentage) of FX present in the resulting sound represented as a value between 0 and 1. For example, a mix of 0 means that only the original sound is heard, a mix of 1 means that only the FX is heard (typically the default) and a mix of 0.5 means that half the original and half of the FX is heard. Default: 1 Must be a value between 0 and 1 inclusively May be changed whilst playing Has slide options to shape changes
pre_mix: | The amount (percentage) of the original signal that is fed into the internal FX system as a value between 0 and 1. With a pre_mix: of 0 the FX is completely bypassed unlike a mix: of 0 where the internal FX is still being fed the original signal but the output of the FX is ignored. The difference between the two is subtle but important and is evident when the FX has a residual component such as echo or reverb. When switching mix: from 0 to 1, the residual component of the FX’s output from previous audio is present in the output signal. With pre_mix: there is no residual component of the previous audio in the output signal. Default: 1 Must be zero or greater May be changed whilst playing Has slide options to shape changes
pre_amp: | Amplification applied to the input signal immediately before it is passed to the FX. Default: 1 Must be zero or greater May be changed whilst playing Has slide options to shape changes
window_size: | Pitch shift works by chopping the input into tiny slices, then playing these slices at a higher or lower rate. If we make the slices small enough and overlap them, it sounds like the original sound with the pitch changed. The window_size is the length of the slices and is measured in seconds. It needs to be around 0.2 (200ms) or greater for pitched sounds like guitar or bass, and needs to be around 0.02 (20ms) or lower for percussive sounds like drum loops. You can experiment with this to get the best sound for your input. Default: 0.2 Must be a value greater than 5.0e-05 May be changed whilst playing Has slide options to shape changes
pitch: | Pitch adjustment in semitones. 1 is up a semitone, 12 is up an octave, -12 is down an octave etc. Maximum upper limit of 24 (up 2 octaves). Lower limit of -72 (down 6 octaves). Decimal numbers can be used for fine tuning. Default: 0 Must be a value greater than or equal to -72,must be a value less than or equal to 24 May be changed whilst playing Has slide options to shape changes
pitch_dis: | Pitch dispersion - how much random variation in pitch to add. Using a low value like 0.001 can help to “soften up” the metallic sounds, especially on drum loops. To be really technical, pitch_dispersion is the maximum random deviation of the pitch from the pitch ratio (which is set by the pitch param) Default: 0.0 Must be a value greater than or equal to 0 May be changed whilst playing Has slide options to shape changes
time_dis: | Time dispersion - how much random delay before playing each grain (measured in seconds). Again, low values here like 0.001 can help to soften up metallic sounds introduced by the effect. Large values are also fun as they can make soundscapes and textures from the input, although you will most likely lose the rhythm of the original. NB - This won’t have an effect if it’s larger than window_size. Default: 0.0 Must be a value greater than or equal to 0 May be changed whilst playing Has slide options to shape changes

## Slide Options

Any parameter that is slidable has three additional options named _slide, _slide_curve, and _slide_shape. For example, 'amp' is slidable, so you can also set amp_slide, amp_slide_curve, and amp_slide_shape with the following effects:

_slide: | Amount of time (in beats) for the parameter value to change. A long parameter_slide value means that the parameter takes a long time to slide from the previous value to the new value. A parameter_slide of 0 means that the parameter instantly changes to the new value. Default: 0
_slide_shape: | Shape of curve. 0: step, 1: linear, 3: sine, 4: welch, 5: custom (use *_slide_curve: opt e.g. amp_slide_curve:), 6: squared, 7: cubed. Default: 5
_slide_curve: | Shape of the slide curve (only honoured if slide shape is 5). 0 means linear and positive and negative numbers curve the segment up and down respectively. Default: 0