diff --git a/packages/core/pattern.mjs b/packages/core/pattern.mjs
index 6e294129e..464e5f233 100644
--- a/packages/core/pattern.mjs
+++ b/packages/core/pattern.mjs
@@ -21,6 +21,7 @@ import {
   numeralArgs,
   parseNumeral,
   pairs,
+  listifyOp,
 } from './util.mjs';
 import drawLine from './drawLine.mjs';
 import { logger } from './logger.mjs';
@@ -1049,7 +1050,8 @@ function _composeOp(a, b, func) {
   const hows = ['In', 'Out', 'Mix', 'Squeeze', 'SqueezeOut', 'Reset', 'Restart', 'Poly'];
 
   // generate methods to do what and how
-  for (const [what, [op, preprocess]] of Object.entries(composers)) {
+  for (const [what, [_op, preprocess]] of Object.entries(composers)) {
+    const op = listifyOp(_op);
     // make plain version, e.g. pat._add(value) adds that plain value
     // to all the values in pat
     Pattern.prototype['_' + what] = function (value) {
diff --git a/packages/core/util.mjs b/packages/core/util.mjs
index b7b1e8413..515f3792d 100644
--- a/packages/core/util.mjs
+++ b/packages/core/util.mjs
@@ -466,6 +466,16 @@ export function getCurrentKeyboardState() {
   return { ...keyState }; // Return a shallow copy of the key state object
 }
 
+export function listifyOp(op) {
+  return function (a, b) {
+    if (!Array.isArray(a)) {
+      return op(a, Array.isArray(b) ? b[0] : b);
+    }
+    b = Array.isArray(b) ? b : [b];
+    return a.map((x, i) => (i < b.length ? op(x, b[i]) : x));
+  };
+}
+
 // Floating point versions, see Fraction for rational versions
 // // greatest common divisor
 // export const gcd = function (x, y, ...z) {