diff --git a/packages/core/signal.mjs b/packages/core/signal.mjs
index c7e143ae6..c9ed21663 100644
--- a/packages/core/signal.mjs
+++ b/packages/core/signal.mjs
@@ -970,10 +970,48 @@ export const keyDown = register('keyDown', function (pat) {
 });
 
 /**
- * A pattern that gives the duration of events that are combined with it.
+ * A pattern measuring the duration of events,
+ * in cycles per event. `cyclesPer` doesn't have structure itself, but takes structure, and therefore
+ * event durations, from the pattern that it is combined with.
+ * For example `cyclesPer.struct("1 1 [1 1] 1")` would give the same as `"0.25 0.25 [0.125 0.125] 0.25"`.
+ * See also its reciprocal, `per`, also known as `perCycle`.
  * @example
- * sound("bd sd [bd bd] sd*4 [- sd] [bd [bd bd]]").note(delta.withValue(x => 1/x + 20))
+ * // Shorter events are lower in pitch
+ * sound("saw saw [saw saw] saw")
+ *   .note(cyclesPer.range(50, 100))
+ * @example
+ * sound("bd sd [bd bd] sd*4 [- sd] [bd [bd bd]]")
+ *   .note(cyclesPer.add(20))
  */
-export const delta = new Pattern(function (state) {
+export const cyclesPer = new Pattern(function (state) {
   return [new Hap(undefined, state.span, state.span.duration)];
 });
+
+/**
+ * A pattern measuring the 'shortness' of events, or in other words, the duration of pattern events,
+ * in events per cycle. `per` doesn't have structure itself, but takes structure, and therefore
+ * event durations, from the pattern that it is combined with.
+ * For example `per.struct("1 1 [1 1] 1")` would give the same as `"4 4 [8 8] 4"`.
+ * See also its reciprocal, `cyclesPer`.
+ * @synonyms perCycle
+ * @example
+ * // Shorter events are more distorted
+ * n("0 0*2 0 0*2 0 [0 0 0]@2").sound("bd")
+ *  .distort(per.div(2))
+ */
+export const per = new Pattern(function (state) {
+  return [new Hap(undefined, state.span, Fraction(1).div(state.span.duration))];
+});
+
+export const perCycle = per;
+
+/**
+ * Like `per` but measures the shortness of events according to an exponential curve. In
+ * particular, where the event duration halves, the
+ * returned value increases by one. `perx.struct("1 1 [1 [1 1]] 1")` would therefore be
+ * the same as `"3 3 [4 [5 5]] 3"`.
+ */
+export const perx = new Pattern(function (state) {
+  const n = Fraction(1).div(state.span.duration);
+  return [new Hap(undefined, state.span, Math.log(n) / Math.log(2) + 1)];
+});
diff --git a/packages/core/test/pattern.test.mjs b/packages/core/test/pattern.test.mjs
index 408ff274b..aaa14bd27 100644
--- a/packages/core/test/pattern.test.mjs
+++ b/packages/core/test/pattern.test.mjs
@@ -740,20 +740,6 @@ describe('Pattern', () => {
       );
     });
   });
-  describe('signal()', () => {
-    it('Can make saw/saw2', () => {
-      expect(saw.struct(true, true, true, true).firstCycle()).toStrictEqual(
-        sequence(0, 1 / 4, 1 / 2, 3 / 4).firstCycle(),
-      );
-
-      expect(saw2.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(-1, -0.5, 0, 0.5).firstCycle());
-    });
-    it('Can make isaw/isaw2', () => {
-      expect(isaw.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(1, 0.75, 0.5, 0.25).firstCycle());
-
-      expect(isaw2.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(1, 0.5, 0, -0.5).firstCycle());
-    });
-  });
   describe('_setContext()', () => {
     it('Can set the hap context', () => {
       expect(
diff --git a/packages/core/test/signal.test.mjs b/packages/core/test/signal.test.mjs
new file mode 100644
index 000000000..b02f8a08b
--- /dev/null
+++ b/packages/core/test/signal.test.mjs
@@ -0,0 +1,61 @@
+/*
+signal.test.mjs - <short description TODO>
+Copyright (C) 2022 Strudel contributors - see <https://codeberg.org/uzu/strudel/src/branch/main/packages/core/test/pattern.test.mjs>
+This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import Fraction from 'fraction.js';
+
+import { describe, it, expect, vi } from 'vitest';
+
+import { saw, saw2, isaw, isaw2, per, perx, cyclesPer } from '../signal.mjs';
+import { fastcat, sequence, State, TimeSpan, Hap } from '../index.mjs';
+
+const st = (begin, end) => new State(ts(begin, end));
+const ts = (begin, end) => new TimeSpan(Fraction(begin), Fraction(end));
+const hap = (whole, part, value, context = {}) => new Hap(whole, part, value, context);
+
+const third = Fraction(1, 3);
+const twothirds = Fraction(2, 3);
+
+const sameFirst = (a, b) => {
+  return expect(a.sortHapsByPart().firstCycle()).toStrictEqual(b.sortHapsByPart().firstCycle());
+};
+
+describe('signal()', () => {
+  it('Can make saw/saw2', () => {
+    expect(saw.struct(true, true, true, true).firstCycle()).toStrictEqual(
+      sequence(0, 1 / 4, 1 / 2, 3 / 4).firstCycle(),
+    );
+
+    expect(saw2.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(-1, -0.5, 0, 0.5).firstCycle());
+  });
+  it('Can make isaw/isaw2', () => {
+    expect(isaw.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(1, 0.75, 0.5, 0.25).firstCycle());
+
+    expect(isaw2.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(1, 0.5, 0, -0.5).firstCycle());
+  });
+});
+
+describe('cyclesPer', () => {
+  it('gives cycles per hap', () => {
+    sameFirst(
+      cyclesPer.struct(true, true, true, fastcat(true, true)),
+      sequence(0.25, 0.25, 0.25, fastcat(0.125, 0.125)).fmap(Fraction),
+    );
+  });
+});
+describe('per', () => {
+  it('gives haps per cycle', () => {
+    sameFirst(per.struct(true, true, true, fastcat(true, true)), sequence(4, 4, 4, fastcat(8, 8)).fmap(Fraction));
+  });
+});
+
+describe('perx', () => {
+  it('gives exponential haps per cycle', () => {
+    sameFirst(
+      perx.struct(true, true, true, fastcat(true, fastcat(true, true))),
+      sequence(3, 3, 3, fastcat(4, fastcat(5, 5))),
+    );
+  });
+});
diff --git a/test/__snapshots__/examples.test.mjs.snap b/test/__snapshots__/examples.test.mjs.snap
index 0b9774205..5f8133ec5 100644
--- a/test/__snapshots__/examples.test.mjs.snap
+++ b/test/__snapshots__/examples.test.mjs.snap
@@ -2539,6 +2539,84 @@ exports[`runs examples > example "cut" example index 0 1`] = `
 ]
 `;
 
+exports[`runs examples > example "cyclesPer" example index 0 1`] = `
+[
+  "[ 0/1 → 1/4 | s:saw note:62.5 ]",
+  "[ 1/4 → 1/2 | s:saw note:62.5 ]",
+  "[ 1/2 → 5/8 | s:saw note:56.25 ]",
+  "[ 5/8 → 3/4 | s:saw note:56.25 ]",
+  "[ 3/4 → 1/1 | s:saw note:62.5 ]",
+  "[ 1/1 → 5/4 | s:saw note:62.5 ]",
+  "[ 5/4 → 3/2 | s:saw note:62.5 ]",
+  "[ 3/2 → 13/8 | s:saw note:56.25 ]",
+  "[ 13/8 → 7/4 | s:saw note:56.25 ]",
+  "[ 7/4 → 2/1 | s:saw note:62.5 ]",
+  "[ 2/1 → 9/4 | s:saw note:62.5 ]",
+  "[ 9/4 → 5/2 | s:saw note:62.5 ]",
+  "[ 5/2 → 21/8 | s:saw note:56.25 ]",
+  "[ 21/8 → 11/4 | s:saw note:56.25 ]",
+  "[ 11/4 → 3/1 | s:saw note:62.5 ]",
+  "[ 3/1 → 13/4 | s:saw note:62.5 ]",
+  "[ 13/4 → 7/2 | s:saw note:62.5 ]",
+  "[ 7/2 → 29/8 | s:saw note:56.25 ]",
+  "[ 29/8 → 15/4 | s:saw note:56.25 ]",
+  "[ 15/4 → 4/1 | s:saw note:62.5 ]",
+]
+`;
+
+exports[`runs examples > example "cyclesPer" example index 1 1`] = `
+[
+  "[ 0/1 → 1/6 | s:bd note:20.166666666666668 ]",
+  "[ 1/6 → 1/3 | s:sd note:20.166666666666668 ]",
+  "[ 1/3 → 5/12 | s:bd note:20.083333333333332 ]",
+  "[ 5/12 → 1/2 | s:bd note:20.083333333333332 ]",
+  "[ 1/2 → 13/24 | s:sd note:20.041666666666668 ]",
+  "[ 13/24 → 7/12 | s:sd note:20.041666666666668 ]",
+  "[ 7/12 → 5/8 | s:sd note:20.041666666666668 ]",
+  "[ 5/8 → 2/3 | s:sd note:20.041666666666668 ]",
+  "[ 3/4 → 5/6 | s:sd note:20.083333333333332 ]",
+  "[ 5/6 → 11/12 | s:bd note:20.083333333333332 ]",
+  "[ 11/12 → 23/24 | s:bd note:20.041666666666668 ]",
+  "[ 23/24 → 1/1 | s:bd note:20.041666666666668 ]",
+  "[ 1/1 → 7/6 | s:bd note:20.166666666666668 ]",
+  "[ 7/6 → 4/3 | s:sd note:20.166666666666668 ]",
+  "[ 4/3 → 17/12 | s:bd note:20.083333333333332 ]",
+  "[ 17/12 → 3/2 | s:bd note:20.083333333333332 ]",
+  "[ 3/2 → 37/24 | s:sd note:20.041666666666668 ]",
+  "[ 37/24 → 19/12 | s:sd note:20.041666666666668 ]",
+  "[ 19/12 → 13/8 | s:sd note:20.041666666666668 ]",
+  "[ 13/8 → 5/3 | s:sd note:20.041666666666668 ]",
+  "[ 7/4 → 11/6 | s:sd note:20.083333333333332 ]",
+  "[ 11/6 → 23/12 | s:bd note:20.083333333333332 ]",
+  "[ 23/12 → 47/24 | s:bd note:20.041666666666668 ]",
+  "[ 47/24 → 2/1 | s:bd note:20.041666666666668 ]",
+  "[ 2/1 → 13/6 | s:bd note:20.166666666666668 ]",
+  "[ 13/6 → 7/3 | s:sd note:20.166666666666668 ]",
+  "[ 7/3 → 29/12 | s:bd note:20.083333333333332 ]",
+  "[ 29/12 → 5/2 | s:bd note:20.083333333333332 ]",
+  "[ 5/2 → 61/24 | s:sd note:20.041666666666668 ]",
+  "[ 61/24 → 31/12 | s:sd note:20.041666666666668 ]",
+  "[ 31/12 → 21/8 | s:sd note:20.041666666666668 ]",
+  "[ 21/8 → 8/3 | s:sd note:20.041666666666668 ]",
+  "[ 11/4 → 17/6 | s:sd note:20.083333333333332 ]",
+  "[ 17/6 → 35/12 | s:bd note:20.083333333333332 ]",
+  "[ 35/12 → 71/24 | s:bd note:20.041666666666668 ]",
+  "[ 71/24 → 3/1 | s:bd note:20.041666666666668 ]",
+  "[ 3/1 → 19/6 | s:bd note:20.166666666666668 ]",
+  "[ 19/6 → 10/3 | s:sd note:20.166666666666668 ]",
+  "[ 10/3 → 41/12 | s:bd note:20.083333333333332 ]",
+  "[ 41/12 → 7/2 | s:bd note:20.083333333333332 ]",
+  "[ 7/2 → 85/24 | s:sd note:20.041666666666668 ]",
+  "[ 85/24 → 43/12 | s:sd note:20.041666666666668 ]",
+  "[ 43/12 → 29/8 | s:sd note:20.041666666666668 ]",
+  "[ 29/8 → 11/3 | s:sd note:20.041666666666668 ]",
+  "[ 15/4 → 23/6 | s:sd note:20.083333333333332 ]",
+  "[ 23/6 → 47/12 | s:bd note:20.083333333333332 ]",
+  "[ 47/12 → 95/24 | s:bd note:20.041666666666668 ]",
+  "[ 95/24 → 4/1 | s:bd note:20.041666666666668 ]",
+]
+`;
+
 exports[`runs examples > example "decay" example index 0 1`] = `
 [
   "[ 0/1 → 1/4 | note:c3 decay:0.1 sustain:0 ]",
@@ -2784,59 +2862,6 @@ exports[`runs examples > example "delaysync" example index 0 1`] = `
 ]
 `;
 
-exports[`runs examples > example "delta" example index 0 1`] = `
-[
-  "[ 0/1 → 1/6 | s:bd note:26 ]",
-  "[ 1/6 → 1/3 | s:sd note:26 ]",
-  "[ 1/3 → 5/12 | s:bd note:32 ]",
-  "[ 5/12 → 1/2 | s:bd note:32 ]",
-  "[ 1/2 → 13/24 | s:sd note:44 ]",
-  "[ 13/24 → 7/12 | s:sd note:44 ]",
-  "[ 7/12 → 5/8 | s:sd note:44 ]",
-  "[ 5/8 → 2/3 | s:sd note:44 ]",
-  "[ 3/4 → 5/6 | s:sd note:32 ]",
-  "[ 5/6 → 11/12 | s:bd note:32 ]",
-  "[ 11/12 → 23/24 | s:bd note:44 ]",
-  "[ 23/24 → 1/1 | s:bd note:44 ]",
-  "[ 1/1 → 7/6 | s:bd note:26 ]",
-  "[ 7/6 → 4/3 | s:sd note:26 ]",
-  "[ 4/3 → 17/12 | s:bd note:32 ]",
-  "[ 17/12 → 3/2 | s:bd note:32 ]",
-  "[ 3/2 → 37/24 | s:sd note:44 ]",
-  "[ 37/24 → 19/12 | s:sd note:44 ]",
-  "[ 19/12 → 13/8 | s:sd note:44 ]",
-  "[ 13/8 → 5/3 | s:sd note:44 ]",
-  "[ 7/4 → 11/6 | s:sd note:32 ]",
-  "[ 11/6 → 23/12 | s:bd note:32 ]",
-  "[ 23/12 → 47/24 | s:bd note:44 ]",
-  "[ 47/24 → 2/1 | s:bd note:44 ]",
-  "[ 2/1 → 13/6 | s:bd note:26 ]",
-  "[ 13/6 → 7/3 | s:sd note:26 ]",
-  "[ 7/3 → 29/12 | s:bd note:32 ]",
-  "[ 29/12 → 5/2 | s:bd note:32 ]",
-  "[ 5/2 → 61/24 | s:sd note:44 ]",
-  "[ 61/24 → 31/12 | s:sd note:44 ]",
-  "[ 31/12 → 21/8 | s:sd note:44 ]",
-  "[ 21/8 → 8/3 | s:sd note:44 ]",
-  "[ 11/4 → 17/6 | s:sd note:32 ]",
-  "[ 17/6 → 35/12 | s:bd note:32 ]",
-  "[ 35/12 → 71/24 | s:bd note:44 ]",
-  "[ 71/24 → 3/1 | s:bd note:44 ]",
-  "[ 3/1 → 19/6 | s:bd note:26 ]",
-  "[ 19/6 → 10/3 | s:sd note:26 ]",
-  "[ 10/3 → 41/12 | s:bd note:32 ]",
-  "[ 41/12 → 7/2 | s:bd note:32 ]",
-  "[ 7/2 → 85/24 | s:sd note:44 ]",
-  "[ 85/24 → 43/12 | s:sd note:44 ]",
-  "[ 43/12 → 29/8 | s:sd note:44 ]",
-  "[ 29/8 → 11/3 | s:sd note:44 ]",
-  "[ 15/4 → 23/6 | s:sd note:32 ]",
-  "[ 23/6 → 47/12 | s:bd note:32 ]",
-  "[ 47/12 → 95/24 | s:bd note:44 ]",
-  "[ 95/24 → 4/1 | s:bd note:44 ]",
-]
-`;
-
 exports[`runs examples > example "density" example index 0 1`] = `
 [
   "[ 0/1 → 1/4 | s:crackle density:0.01 ]",
@@ -7966,6 +7991,51 @@ exports[`runs examples > example "penv" example index 0 1`] = `
 ]
 `;
 
+exports[`runs examples > example "per" example index 0 1`] = `
+[
+  "[ 0/1 → 1/7 | n:0 s:bd distort:3.5 ]",
+  "[ 1/7 → 3/14 | n:0 s:bd distort:7 ]",
+  "[ 3/14 → 2/7 | n:0 s:bd distort:7 ]",
+  "[ 2/7 → 3/7 | n:0 s:bd distort:3.5 ]",
+  "[ 3/7 → 1/2 | n:0 s:bd distort:7 ]",
+  "[ 1/2 → 4/7 | n:0 s:bd distort:7 ]",
+  "[ 4/7 → 5/7 | n:0 s:bd distort:3.5 ]",
+  "[ 5/7 → 17/21 | n:0 s:bd distort:5.25 ]",
+  "[ 17/21 → 19/21 | n:0 s:bd distort:5.25 ]",
+  "[ 19/21 → 1/1 | n:0 s:bd distort:5.25 ]",
+  "[ 1/1 → 8/7 | n:0 s:bd distort:3.5 ]",
+  "[ 8/7 → 17/14 | n:0 s:bd distort:7 ]",
+  "[ 17/14 → 9/7 | n:0 s:bd distort:7 ]",
+  "[ 9/7 → 10/7 | n:0 s:bd distort:3.5 ]",
+  "[ 10/7 → 3/2 | n:0 s:bd distort:7 ]",
+  "[ 3/2 → 11/7 | n:0 s:bd distort:7 ]",
+  "[ 11/7 → 12/7 | n:0 s:bd distort:3.5 ]",
+  "[ 12/7 → 38/21 | n:0 s:bd distort:5.25 ]",
+  "[ 38/21 → 40/21 | n:0 s:bd distort:5.25 ]",
+  "[ 40/21 → 2/1 | n:0 s:bd distort:5.25 ]",
+  "[ 2/1 → 15/7 | n:0 s:bd distort:3.5 ]",
+  "[ 15/7 → 31/14 | n:0 s:bd distort:7 ]",
+  "[ 31/14 → 16/7 | n:0 s:bd distort:7 ]",
+  "[ 16/7 → 17/7 | n:0 s:bd distort:3.5 ]",
+  "[ 17/7 → 5/2 | n:0 s:bd distort:7 ]",
+  "[ 5/2 → 18/7 | n:0 s:bd distort:7 ]",
+  "[ 18/7 → 19/7 | n:0 s:bd distort:3.5 ]",
+  "[ 19/7 → 59/21 | n:0 s:bd distort:5.25 ]",
+  "[ 59/21 → 61/21 | n:0 s:bd distort:5.25 ]",
+  "[ 61/21 → 3/1 | n:0 s:bd distort:5.25 ]",
+  "[ 3/1 → 22/7 | n:0 s:bd distort:3.5 ]",
+  "[ 22/7 → 45/14 | n:0 s:bd distort:7 ]",
+  "[ 45/14 → 23/7 | n:0 s:bd distort:7 ]",
+  "[ 23/7 → 24/7 | n:0 s:bd distort:3.5 ]",
+  "[ 24/7 → 7/2 | n:0 s:bd distort:7 ]",
+  "[ 7/2 → 25/7 | n:0 s:bd distort:7 ]",
+  "[ 25/7 → 26/7 | n:0 s:bd distort:3.5 ]",
+  "[ 26/7 → 80/21 | n:0 s:bd distort:5.25 ]",
+  "[ 80/21 → 82/21 | n:0 s:bd distort:5.25 ]",
+  "[ 82/21 → 4/1 | n:0 s:bd distort:5.25 ]",
+]
+`;
+
 exports[`runs examples > example "perlin" example index 0 1`] = `
 [
   "[ 0/1 → 1/8 | s:hh cutoff:500 ]",