diff --git a/packages/core/strudel.mjs b/packages/core/strudel.mjs
index 5f659e886..a09657534 100644
--- a/packages/core/strudel.mjs
+++ b/packages/core/strudel.mjs
@@ -1,5 +1,5 @@
 import Fraction from './fraction.mjs';
-import { isNote, toMidi, compose, removeUndefineds, flatten, id, listRange, curry } from './util.mjs';
+import { isNote, toMidi, compose, removeUndefineds, flatten, id, listRange, curry, objectify } from './util.mjs';
 
 class TimeSpan {
   constructor(begin, end) {
@@ -515,7 +515,7 @@ class Pattern {
   }
 
   union(other) {
-    return this._opleft(other, (a) => (b) => Object.assign({}, a, b));
+    return this._opleft(other, (a) => (b) => Object.assign({}, objectify(a), objectify(b)));
   }
 
   _bindWhole(choose_whole, func) {
diff --git a/packages/core/test/util.test.mjs b/packages/core/test/util.test.mjs
index 5e8c906e7..aad7a37ce 100644
--- a/packages/core/test/util.test.mjs
+++ b/packages/core/test/util.test.mjs
@@ -1,5 +1,5 @@
 import { strict as assert } from 'assert';
-import { isNote, tokenizeNote, toMidi, mod, compose } from '../util.mjs';
+import { isNote, tokenizeNote, toMidi, mod, compose, dirtify } from '../util.mjs';
 
 describe('isNote', () => {
   it('should recognize notes without accidentals', () => {
@@ -96,3 +96,28 @@ describe('compose', () => {
     assert.equal(compose(addS('a'), addS('b'))('x'), 'xab');
   });
 });
+
+describe('dirtify', () => {
+  it('should offset plain number', () => {
+    assert.deepStrictEqual(dirtify(61), { n: 1 });
+    assert.deepStrictEqual(dirtify(60), { n: 0 });
+  });
+  it('should parse note string as midi number', () => {
+    assert.deepStrictEqual(dirtify('c4'), { n: 0 });
+    assert.deepStrictEqual(dirtify('c5'), { n: 12 });
+  });
+  it('should use non note string as sound', () => {
+    assert.deepStrictEqual(dirtify('bd'), { s: 'bd' });
+  });
+  it('should keep objects as is', () => {
+    assert.deepStrictEqual(dirtify({ s: 'bd' }), { s: 'bd' });
+    assert.deepStrictEqual(dirtify({ n: 7 }), { n: 7 });
+    assert.deepStrictEqual(dirtify({ n: 7, room: 0.5 }), { n: 7, room: 0.5 });
+  });
+  it('should dirtify .value', () => {
+    assert.deepStrictEqual(dirtify({ value: 61 }), { n: 1 });
+    assert.deepStrictEqual(dirtify({ value: 'c5' }), { n: 12 });
+    assert.deepStrictEqual(dirtify({ value: 'bd' }), { s: 'bd' });
+    assert.deepStrictEqual(dirtify({ value: 61, room: 0.5 }), { n: 1, room: 0.5 });
+  });
+});
diff --git a/packages/core/util.mjs b/packages/core/util.mjs
index 2de7a8e6b..2a77b284f 100644
--- a/packages/core/util.mjs
+++ b/packages/core/util.mjs
@@ -83,3 +83,42 @@ export function curry(func, overload) {
   }
   return fn;
 }
+
+// this functions just makes sure non objects values are wrapped in { value }
+export function objectify(value) {
+  if (typeof value === 'object' && !Array.isArray(value)) {
+    return value; // do nothing if its already an object
+  }
+  return { value };
+}
+
+// maybe move this to osc?
+// turns value into object that is the right format superdirt osc
+export function dirtify(val) {
+  const obj = objectify(val);
+  if (obj.n && typeof obj.n === 'string') {
+    return { ...obj, ...objectify(obj.n) };
+  }
+  const { value, ...rest } = obj;
+  if (typeof value === 'undefined') {
+    return rest;
+  }
+  const isNumber = typeof value === 'number';
+  const isMidi = typeof value === 'string' && isNote(value);
+  if (isNumber || isMidi) {
+    const numberOffset = -60; // tidal 0 = midi 60
+    const n = (isNumber ? value : toMidi(value)) + numberOffset;
+    if (rest.n) {
+      console.warn(`dirtify: n is already defined as "${rest.n}", overwriting with value "${n}"`);
+    }
+    return { ...rest, n };
+  }
+  if (typeof value === 'string') {
+    // not a note => should be a sound
+    return { ...rest, s: value };
+  }
+  console.warn(`dirtify: ignored value "${value}"`);
+  // what lands here?
+  // throw new Error('cannot objectify: ' + value);
+  return {};
+}