diff --git a/packages/core/pattern.mjs b/packages/core/pattern.mjs
index dcf5da1b..370776f3 100644
--- a/packages/core/pattern.mjs
+++ b/packages/core/pattern.mjs
@@ -2392,3 +2392,29 @@ export const ref = (accessor) =>
pure(1)
.withValue(() => reify(accessor()))
.innerJoin();
+
+let fadeGain = (p) => (p < 0.5 ? 1 : 1 - (p - 0.5) / 0.5);
+
+/**
+ * Cross-fades between left and right from 0 to 1:
+ * - 0 = (full left, no right)
+ * - .5 = (both equal)
+ * - 1 = (no left, full right)
+ *
+ * @name xfade
+ * @example
+ * xfade(s("bd*2"), "<0 .25 .5 .75 1>", s("hh*8"))
+ */
+export let xfade = (a, pos, b) => {
+ pos = reify(pos);
+ a = reify(a);
+ b = reify(b);
+ let gaina = pos.fmap((v) => ({ gain: fadeGain(v) }));
+ let gainb = pos.fmap((v) => ({ gain: fadeGain(1 - v) }));
+ return stack(a.mul(gaina), b.mul(gainb));
+};
+
+// the prototype version is actually flipped so left/right makes sense
+Pattern.prototype.xfade = function (pos, b) {
+ return xfade(this, pos, b);
+};
diff --git a/test/__snapshots__/examples.test.mjs.snap b/test/__snapshots__/examples.test.mjs.snap
index 0963638f..e920d931 100644
--- a/test/__snapshots__/examples.test.mjs.snap
+++ b/test/__snapshots__/examples.test.mjs.snap
@@ -5235,6 +5235,51 @@ exports[`runs examples > example "withValue" example index 0 1`] = `
]
`;
+exports[`runs examples > example "xfade" example index 0 1`] = `
+[
+ "[ 0/1 → 1/8 | s:hh gain:0 ]",
+ "[ 0/1 → 1/2 | s:bd gain:1 ]",
+ "[ 1/8 → 1/4 | s:hh gain:0 ]",
+ "[ 1/4 → 3/8 | s:hh gain:0 ]",
+ "[ 3/8 → 1/2 | s:hh gain:0 ]",
+ "[ 1/2 → 5/8 | s:hh gain:0 ]",
+ "[ 1/2 → 1/1 | s:bd gain:1 ]",
+ "[ 5/8 → 3/4 | s:hh gain:0 ]",
+ "[ 3/4 → 7/8 | s:hh gain:0 ]",
+ "[ 7/8 → 1/1 | s:hh gain:0 ]",
+ "[ 1/1 → 9/8 | s:hh gain:0.5 ]",
+ "[ 1/1 → 3/2 | s:bd gain:1 ]",
+ "[ 9/8 → 5/4 | s:hh gain:0.5 ]",
+ "[ 5/4 → 11/8 | s:hh gain:0.5 ]",
+ "[ 11/8 → 3/2 | s:hh gain:0.5 ]",
+ "[ 3/2 → 13/8 | s:hh gain:0.5 ]",
+ "[ 3/2 → 2/1 | s:bd gain:1 ]",
+ "[ 13/8 → 7/4 | s:hh gain:0.5 ]",
+ "[ 7/4 → 15/8 | s:hh gain:0.5 ]",
+ "[ 15/8 → 2/1 | s:hh gain:0.5 ]",
+ "[ 2/1 → 17/8 | s:hh gain:1 ]",
+ "[ 2/1 → 5/2 | s:bd gain:1 ]",
+ "[ 17/8 → 9/4 | s:hh gain:1 ]",
+ "[ 9/4 → 19/8 | s:hh gain:1 ]",
+ "[ 19/8 → 5/2 | s:hh gain:1 ]",
+ "[ 5/2 → 21/8 | s:hh gain:1 ]",
+ "[ 5/2 → 3/1 | s:bd gain:1 ]",
+ "[ 21/8 → 11/4 | s:hh gain:1 ]",
+ "[ 11/4 → 23/8 | s:hh gain:1 ]",
+ "[ 23/8 → 3/1 | s:hh gain:1 ]",
+ "[ 3/1 → 25/8 | s:hh gain:1 ]",
+ "[ 3/1 → 7/2 | s:bd gain:0.5 ]",
+ "[ 25/8 → 13/4 | s:hh gain:1 ]",
+ "[ 13/4 → 27/8 | s:hh gain:1 ]",
+ "[ 27/8 → 7/2 | s:hh gain:1 ]",
+ "[ 7/2 → 29/8 | s:hh gain:1 ]",
+ "[ 7/2 → 4/1 | s:bd gain:0.5 ]",
+ "[ 29/8 → 15/4 | s:hh gain:1 ]",
+ "[ 15/4 → 31/8 | s:hh gain:1 ]",
+ "[ 31/8 → 4/1 | s:hh gain:1 ]",
+]
+`;
+
exports[`runs examples > example "zoom" example index 0 1`] = `
[
"[ 0/1 → 1/6 | s:hh ]",
diff --git a/website/src/pages/learn/effects.mdx b/website/src/pages/learn/effects.mdx
index 30804240..b1323a8e 100644
--- a/website/src/pages/learn/effects.mdx
+++ b/website/src/pages/learn/effects.mdx
@@ -156,6 +156,10 @@ There is one filter envelope for each filter type and thus one set of envelope f
+## xfade
+
+
+
# Panning
## jux