Control Parameters
Besides functions that control time, we saw earlier that functions like note
and cutoff
control different parameters (short params) of an event.
Letโs now look more closely at how these param(eter) functions
work.
Parameter Functions
A very powerful feature of tidal patterns is that each parameter can be controlled independently:
In this example, the parameters note
, cutoff
, gain
and s
are controlled independently by either patterns or plain values (numbers / text).
After pressing play, we can observe the time and parameter values of each event (hap) in the output created by .log()
.
Plain vs Parameterized Values
Patterns that are not wrapped inside a param function will contain unlabeled plain values
:
This will not generate any sound output, because Strudel could only guess which param is meant by these letters.
Now compare that to the version wrapped in note
:
Now it is clear that these letters are meant to be played as notes.
Under the hood, the note
function (as well as all other param functions)
will wrap each plain value in an object. If the note function did not exist, we would need to write:
This will have the same output, though it is rather unwieldy to read and write.
Wrapping Parameter Functions
To avoid too much nesting, param functions can also be chained like this:
This is equivalent to note(cat('c','e','g')).log()
.
You can use this with any function that declares a type (like n
, s
, note
, freq
etc), just make sure to leave the parens empty!
Plain Value Modification
Patterns of plain values can be modified with any of the following operators:
Here, the add function modifies the numbers on the left. Again, there is no output because these numbers have no meaning without a param.
Param Value Modification
To modify a parameter value, you can either:

Use the operator on the plain value pattern, inside the param function:

Similarly, use the operator on the plain value pattern and wrap it later:

Specify which param should be modified inside the operator function:

Modify all numeral params:
Which of these 3 ways to use strongly depends on the context!
Note that the order of chaining param functions also matters!
In the last example, the room
value would not have changed if it was applied later:
This shows how the execution of the chained functions goes from left to right.
In this case, the .add
will only modify whatโs on the left side.
Operators
This group of functions allows to modify the value of events.
add
Assumes a pattern of numbers. Adds the given number to each item in the pattern.
// Here, the triad 0, 2, 4 is shifted by different amounts n("0 2 4".add("<0 3 4 0>")).scale("C:major") // Without add, the equivalent would be: // n("<[0 2 4] [3 5 7] [4 6 8] [0 2 4]>").scale("C:major")
// You can also use add with notes: note("c3 e3 g3".add("<0 5 7 0>")) // Behind the scenes, the notes are converted to midi numbers: // note("48 52 55".add("<0 5 7 0>"))
sub
Like add, but the given numbers are subtracted.
n("0 2 4".sub("<0 1 2 3>")).scale("C4:minor") // See add for more information.
mul
Multiplies each number by the given factor.
"<1 1.5 [1.66, <2 2.33>]>*4".mul(150).freq()
div
Divides each number by the given factor.
round
Assumes a numerical pattern. Returns a new pattern with all values rounded to the nearest integer.
n("0.5 1.5 2.5".round()).scale("C:major")
floor
Assumes a numerical pattern. Returns a new pattern with all values set to
their mathematical floor. E.g. 3.7
replaced with to 3
, and 4.2
replaced with 5
.
note("42 42.1 42.5 43".floor())
ceil
Assumes a numerical pattern. Returns a new pattern with all values set to
their mathematical ceiling. E.g. 3.2
replaced with 4
, and 4.2
replaced with 4
.
note("42 42.1 42.5 43".ceil())
range
Assumes a numerical pattern, containing unipolar values in the range 0 .. 1. Returns a new pattern with values scaled to the given min/max range. Most useful in combination with continuous patterns.
s("[bd sd]*2,hh*8") .cutoff(sine.range(500,4000))
rangex
Assumes a numerical pattern, containing unipolar values in the range 0 .. 1 Returns a new pattern with values scaled to the given min/max range, following an exponential curve.
s("[bd sd]*2,hh*8") .cutoff(sine.rangex(500,4000))
range2
Assumes a numerical pattern, containing bipolar values in the range 1 .. 1 Returns a new pattern with values scaled to the given min/max range.
s("[bd sd]*2,hh*8") .cutoff(sine2.range2(500,4000))
ratio
Allows dividing numbers via list notation using ":". Returns a new pattern with just numbers.
ratio("1, 5:4, 3:2").mul(110) .freq().s("piano")
Custom Parameters
You can also create your own parameters:
Multiple params can also be created in a more consice way, using createParams
:
Note that these params will not do anything until you give them meaning in your custom output!
From modifying parameters we transition to the concept of Signals.