the minions are coming tho

[code]

This sporthling leverages the ability to use tables as sequencers and patterns in Sporth. There are a two melodic "themes" played layered along side some white noise bursts.

Variables and Tables

Before anything is started, the variables and tables are declared.

• A variable called clk is used to store clock data.
• A table called seq stores MIDI note numbers. for the main melodic sequence.
  

• A variable called nt is used to store a midi note value. Here it is being set to midi note number 55.

  clk var seq "74 72 70 69 67" genvals bs "43 41 39 38 43 45 46 48" genvals nt 55 varset

The Clock

The clock used for all the timing elements in the patch are set using metro, whose rate is randomly warped using randi and randh. I use this drifting clock approach in patches mainly to break any "groove" that would occur. In breaking the groove, the piece becomes more fluid and organic.

 0.5 10 (1 3 5 randh) randi metro _clk set 

Lead

The main element in this patch is this lead sound. It is a surprisingly complex element comprised of two sound sources blended together. Each component of the lead sound has been broken into into sections.

Envelope 1

At the time of making this patch, tseg was a newly added soundpipe module and sporth ugen that I wanted to build an intuition about. For this reason, all the envelopes generated in this patch were created using tseg. It is worth examining one of envelopes in detail.

tseg is a trigger-based line generator, capable of generating lines with various kinds of slopes. These can range from convex exponential shapes to concave exponential shapes.

The first argument is a trigger signal, which will make tseg jump to a given value.

 _clk get 

The value it jumps to is the second argument. An envelope jumps to either 1 or 0. To generate this, the clock signal is duplicated and fed into tog.

 dup tog 

The duration of tseg is the third argument. It is being fed with the triggerable random number generator trand driven by the clock signal. The range of time is between 5 and 500 milliseconds.

 _clk get 0.005 0.5 trand 

The fourth argument determines the curve of the line segment. This value is being set between -10 and 5. Negative values will produce convex envelope attacks, while positive values will produce concave envelope attacks. The larger the value, the steeper the curve in either direction.

 _clk get -10 5 trand 

Finally, tseg is called. The last and final parameter is the initial value for the line segment, which has been to 0. tseg produces a value and pushes it onto the stack for later use.

 0 tseg 

Square

One of the timbres used is a bandlimited square wave. For starters, it has a pitch of an 'E' above middle C (midi note number 74) and an amplitude of 0.3

 74 mtof 0.3 

The pulse width of the square wave is modulated with another envelope generator via tseg. As it turns out, this envelope generator is identical to the envelope described above.

 _clk get 0.5 maytrig dup tog 
 _clk get 0.005 0.5 trand 
 _clk get -10 5 trand 
 0 tseg 

The output of tseg is in the range 0-1, and since 0 and 1 exactly are out of range for square, it is rescaled to be between 0.1 and 0.5.

 0.1 0.5 scale

square is called, and the value produced is pushed onto the stack. At this point the stack contents are the envelope and the square.

 square

FM

The second timbral contribution to the lead sound is a FM oscillator pair. The frequency of this oscillator is set using a sequence built using the seq table from before and tseq. Instead of using the clock signal from before, the FM using a new clock signal generated using metro.

 4 metro 0.5 maytrig 0 _seq tseq 

Oftentimes the jumps caused by the sequencer lead to undesirable clicks. the steps between the notes are smoothed via a portamento filter port, then fed into mtof to be converted into a frequency.

 0.01 port mtof 

The rest of the FM oscillator pair fm is fairly vanilla. It has an amplitude of 0.4, with a 2:7 C:M ratio, and a modulation index of 5. This particular C:M ratio is particularly bright with spread out harmonics. The higher-than-usual modulation index adds to the brightness of the FM sound.

 0.4 2 7 5 fm 

fm computes a sample and pushes that value onto the stack. Now there is an envelope signal, a square signal, and an FM signal.

Blending

The square signal and FM signal generated in the previous two subsections are to be blended together via a linear crossfade called cf. The position of the crossfade is determined via randi.

 0 0.8 1 randi cf

To mellow things out, the lead is fed through a butterworth lowpass filter. The cutoff frequency of the lowpass filter is determined via a randi ugen in the range 700 to 1000, whose rate is 13 times a second.

 700 1000 (13 bpm2rate) randi butlp

The envelope generated from before is multiplied with the lead signal.

 *

Envelope 2

The signal generated above works, but there are now spaces or pauses. This gets fatiguing to the ears very quickly. To add space, the signal is hit with another envelope buit to add space. The amount influence this envelope has is modulated as well via another crossfade cf, crossing between a steady signal of 1 and the signal itself. The crossfade first begins with such a steady signal. It is just a value of 1.

 1 

The second signal in the crossfade is the second envelope. A new metronome metro, whose rate is randomly determined via randh, is fed into a toggle signal tog. To smooth the transitions generated by tog, it is fed into a portamento filter.

 (30 50 1 randh metro tog 0.001 port) 
 

The position randomly switches between the steady state signal and the envelope with a signal created from a metro, a maygate, and a portamento to smooth things out.

 10 metro 0.4 maygate 0.003 port

The crossfaded signal is produced and multiplied with the current signal.

 cf * 

Feedback Delay

Some feedback delay is added to the lead sound. The feedback amount is set to 900 milliseconds, and the delay time is 1.1 seconds. It is attenuated and added to the dry signal. This summed signal is also attenuated as well to make room for the bass.

 dup 0.9 1.1 delay -6 ampdb *  + -6 ampdb * 

Bass

The bass sound used is your run-of-the-mill supersaw subtractive bass. Nothing too unusual is happening here, but it still sounds great.

Sequencer

Yet another independent clock signal is generated for the bass sequencer, this time using dmetro set to 90 beats per minute via bpm2dur

 90 bpm2dur dmetro 

The trigger signal is fed into a trigger divider tdiv, which takes the clock signal and only spits out a trigger every 4 ticks. This effectively turns a quarter note signal into a signal that ticks once per measure in 4/4 time.

 4 0 tdiv 

This clock signal is made even more sparse when it is fed into a maytrig with a 40% probability. tick is added onto this signal to ensure that there is a starting note when the patch begins.

 0.8 maytrig tick + 

The rest of tseq is outlined below. Tseq is set to mode 0, which means move in sequential order.

 0 _bs tseq 

To smooth the jumps between notes, a portamento filter port is used.

 0.01 port 

The signal generated is to be used multiple times, so to save on stack operations, it is stored into the variable nt.

 _nt set

Sawtooths

Using the sequencer signal generated above, three sawtooth oscillators are summed together. The two detuned oscillators are shifted one octave below.

 _nt get mtof 0.1 saw 
 _nt get 12.1 - mtof 0.2 saw 
 _nt get 11.9 - mtof 0.1 saw + + 

Filters

The output signal the bass is fed into a butterworth lowpass filter, whose cutoff is being modulated via rand.

 300 900 0.2 randi butlp +

White Noise

The final signal in this patch is a enveloped white noise burst. It is not too shocking that one of the elements is white noise.

 0.4 noise 

The envelope signal has a clock signal generated via metro.

 15 metro 

This clock signal is duplicated and fed into tdiv to output a tick every 4 ticks on the input. This signal is fed into a maygate, which is used to effectively shut the noise on and off.

 dup 4 0 tdiv 0.2 maygate * 

swap is utilized to get the copy of the clock signal created. It is fed into a maytrig to make it more sparse.

 swap 0.9 maytrig 

This trigger signal is then fed into tgate. When triggered, tgate will produce a gate signal for .5 millseconds. This tiny gate is then smoothed out using port and multiplied with the white noise signal to get a rhythmic clackity click.

 0.0005 tgate 0.001 port *  

Finally, this white noise signal is added into everything that has occured before it.

 +

Effects

The effect chain consists of a reverb module and a peak limiter. Before any signals are processed, a copy of the signal is made. The signal is then fed into zrev, the simplified zita reverb module ugen. Before it is fed in, it is sent through a high pass filter. This is to give the dry bass sound more clarity and to make things less muddy.

 200 buthp dup 20 10 4000 zrev drop -3 ampdb * +

Before being sent to the speakers, the final mix is sent through a peak limiter and bumped up 3db.

 0.1 0.001 -3 peaklim 3 ampdb *