Arithmetic Events

Every numerical parameter has an associated set of arithmetic events (see tutorial chapter "Event-Arithmetic").

Thus, the rate parameters has rate-mul (multiplication), rate-add (addition), rate-div (division) and rate-sub (subtraction) associated.

(sx 'foo #t
    (pear (freq-mul 1.5) ;; transpose the incoming event stream a (pure) fifth up by multiplying frequency
        (nuc 'bar (saw 'a2))))

(sx 'foo #t
    (pear (rate-div 2) ;; transpose the incoming event stream an octave down by dividing playback rate
        (nuc 'bar (violin 'a3 :sus 200))))

You can use the :idx parameter to select a specific type (as of 0.0.11, select the specific oscillator for mosc or the peak filter for sample events):

;; only modify frequency of second oscillator
(sx 'ba #t 
    (pear (freq-mul 2 :idx 2)
        (nuc 'fa (mosc :osc1 'saw :osc2 'saw :freq1 100 :freq2 200))))

If no index is specified, the arithmetic event will be applied to all entities that support it:

;; modify frequency of all oscillators
(sx 'ba #t 
    (pear (freq-mul 2)
        (nuc 'fa (mosc :osc1 'saw :osc2 'saw :freq1 100 :freq2 200))))

Special Events and Shorthands

Keys

Specify lookup keys for samples, works with add and sub.

(sx 'ba #t
  (pear
    :p 10 (keys-add 'ff) ;; with a chance of 10%, use a more restricted search
    (nuc 'tra (piano 'a3))))

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MIDI Notes

The functions midi-mul, midi-add, midi-sub and midi-div allow you to work with midi notes (from note event) the same way you'd work with frequencies in Mégra:

(sx 'ba #t
  (cmp
    (mapper to-piano)
    (pear :p 12 (midi-add 2) :p 12 (midi-sub 3))
    (nuc 'tra (note 44 4)) ;; midi note 44, quarter
  ))

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random-sample or rands - Pick a Random Sample Every Time

Pick a random sample every time:

(sx 'ba #t
  (pear
    (rands) ;; pick a random bassdrum every time
    (nuc 'tra (bd))))

---

sample-number or sno - Sample Number

Pick a sample by its position in the sample folder.

(sx 'ba #t
  (cmp
    (loop 'tro (sno 1) (sno 2) (sno 3)) ;; loop over the first three samples in the folder
    (nuc 'tra (bd)))
)

Transpose

The transpose event multiplies the incoming frequency or playback rate by half-tones (currently there's only equal-tempered tuning).

Syntax

(transpose <half-tones>) or (tpo <half-tones>).

Example:

(sx 'foo #t
    (pear (transpose 4) ;; transpose the incoming event stream a major third up
        (nuc 'bar (saw 'a2))))

(sx 'foo #t
    (pear (transpose 4) ;; works the same on sample events ...
        (nuc 'bar (violin 'a3 :sus 200))))