euclidean beat sin clojure

core.clj

(ns clojtest.core)

(defn rotate-left
  ([coll]   (rotate-left 1 coll))
  ([n coll] (concat (drop n coll) (take n coll))))

(defn euclidean-beat
  ([hit-length length rotation]
   (rotate-left rotation
                (euclidean-beat hit-length length)))
  ([hit-length] (euclidean-beat hit-length 16))
  ([hit-length length]
   (take length
         (flatten (repeat (cons 1 (repeat (- hit-length 1) 0)))))))

(defn sum [xs ys] (map (fn [x y] (+ x y)) xs ys))

(reduce sum [(euclidean-beat 3)
             (euclidean-beat 3 16 3)
             (euclidean-beat 5)
             (euclidean-beat 4)])