Modulate parameters with oscillators

Oscillators are continuously varying patterns. Unless otherwise stated, oscillators give minimum values of 0 and maximum values of 1, and repeat once per cycle.

What is an oscillator?

Oscillators are continuous patterns, which means they don’t have any structure, and must be used with a pattern that does. For example d1 $ sound "bd*8" >| pan sine won’t work well, because the >| operator instructs Tidal to take structure from the right, and sine doesn’t have any structure, so Tidal will simply trigger events at a fixed rate (depending on your configuration, this might be very fast). d1 $ sound "bd*8" |> pan sine is better, because |> takes structure from the left, so eight kick drums will play, with pan values sampled from the sine wave for each of the eight events. Where a pattern has the type Fractional a => Pattern a, that means that they can be used both as floating point numbers or (rational) time values.

Using oscillators

Periodic oscillators

Sine

Type: sine :: Fractional a => Pattern a

sine is a sinusoidal wave. Playing this example, you should hear the sound slowly moving from your left to your right speaker:

d1 $ sound "bd*8" # pan sine

Cosine

Type: cosine :: Fractional a => Pattern a

A cosine wave, is a sine shifted in time by a quarter of a cycle. It sounds similar to the sine above:

d1 $ sound "bd*8" # pan cosine # speed (sine + 0.5)

Square

Type: square :: Fractional a => Pattern a

A Square wave, starting at 0, then going up to 1 halfway through a cycle.

d1 $ sound "bd*8" # pan (cat [square, sine])

Tri

Type: tri :: Fractional a => Pattern a

A triangle wave, starting at 0, then linearly rising to 1 halfway through a cycle, then down again:

d1 $ sound "bd*16" # speed (slow 2 $ range 0.5 2 tri)

Saw

Type: saw :: Fractional a => Pattern a

A sawtooth wave starting at 0, then linearly rising to 1 over one cycle, then jumping back to 0:

d1 $ sound "bd*8" # pan (slow 2 saw)

Isaw

Type: isaw :: Fractional a => Pattern a

An inverted sawtooth, starting at 1, then linearly falling to 0 over one cycle, then jumping back to 1:

d1 $ sound "bd*8" # pan (slow 2 isaw)

Smooth

Type: smooth :: Fractional a => Pattern a -> Pattern a

Smooth receives a pattern of numbers and linearly goes from one to the next, passing through all of them. As time is cycle-based, after reaching the last number in the pattern, it will smoothly go to the first one again.

d1 $ sound "bd*4" # pan (slow 4 $ smooth "0 1 0.5 1")

Note how the sound goes gradually from left to right, then to the center, then to the right again, and finally comes back to the left.

Non-periodic oscillators

Rand

Type: rand :: Fractional a => Pattern a

An infinitely detailed stream of (pseudo-)random numbers. See the rand reference page for more details.

d1 $ sound "bd*8" # pan rand

Irand

Type: irand :: Num a => Pattern Int -> Pattern a

A function from an integer (giving the maximum) to a stream of (pseudo-)random integer numbers. For more details, head to the rand reference page:

d1 $ sound "drum*8" # n (irand 8)

Scaling oscillators

By default, the oscillators will output values scaled between 0 and 1. You might want to use bigger or smaller values. You might want, for instance, to modulate the frequency of a filter or select a random midi note between 0 and 127. To do so, you can use the range function:

d1 $ s "bass:5*8" # lpf (range 200 5000 $ sine)

Speeding up/down oscillators

Oscillators are patterns! It means that you can speed them up or down using the same function as usual (fast, slow, etc..):

d1 $ s "bass:5*8" # lpf (slow 4 $ range 200 5000 $ sine)