TidalCycles snowball applies a transform iteratively to accumulate layers, like a feedback-processed delay

snowball depth (+) transform start applies transform to the starting pattern, then combines the result with the previous using the combiner function, repeating depth times. The metaphor is a feedback delay where each echo is more processed than the last: each layer has transform applied an additional time, and all layers are combined (e.g., added with +). In the canonical example, snowball 8 (+) (slow 2 . rev) creates 8 layers of a melody, each layer slowed by 2 and reversed, all added together. This produces rhythmic accumulation and timbral richness impossible with single-pass transforms. Understanding this function requires grasping function composition and the concept of recursive pattern combination.

Examples

d1 $ note (
  scale "hexDorian"
  $ snowball 8 (+) (slow 2 . rev) "0 ~ . -1 _ 5 3 4 . ~ -2")
  # s "gtr"

Assessment

Explain what happens at each of the 8 iterations in snowball 8 (+) (slow 2 . rev) "0 1 2". What does the + combiner function do here? How would changing (slow 2 . rev) to (fast 2) change the texture?