Glissando texture

An example of using time-varying resampling to generate a polyphonic texture.

glissando_texture.bell

## Import an audio buffer from the file 'poem.wav'
$buf = importaudio('poem.wav');
## Define a set of transpositions for retuning, centered around 0
$cents = (0 2 4 7 9) * 100;
$cents = $cents - mean($cents);
## Convert cents to ratios
$ratios = c2r($cents);
## Specify the number of voices for processing
$numvoices = 5;
## Retune the buffer by mapping it to a neutral pitch grid
$buf = $buf.process(retune(@pitchgrid 0 @ambiencethreshold -10));
## Iterate over the number of voices for granular processing
for $v in 1...$numvoices do (
    ## Map the voice index to a stereo pan position
    $pan = scale($v, 1, $numvoices, 0, 1);
    ## Randomly determine the envelope size for pitch glissando
    $envsize = random(10, 20);
    ## Generate a breakpoint function (BPF) for glissando effects
    $glissbpf = for $x in 0...($envsize - 1) collect (
        ## Select a random resampling ratio
        $ratio = choose($ratios);
        ## Create the BPF entry
        [$x 1 / $ratio 0.95] 
    );
    ## Create a resampling effect using the generated glissando BPF
    $fx = resample($glissbpf);
    ## Apply the effect to the buffer and transcribe with pan settings
    $buf.process($fx).transcribe(
        ## Set onset time to 0
        @onset 0
        ## Apply pan position for spatial distribution
        @pan $pan
    ) 
);
## Render the processed audio with normalization and reverb
render(
    @play 1 @process normalize(-3) freeverb(
        ## Set reverb room size
        @roomsize 0.7
        ## Control wet/dry mix of reverb
        @wet 0.025
        ## Adjust damping for high-frequency absorption
        @damp 1
        ## Set stereo width for the effect
        @width 1
    ) 
)