diff --git a/api/smart_key_notation_test.go b/api/smart_key_notation_test.go
new file mode 100644
index 0000000..50df179
--- /dev/null
+++ b/api/smart_key_notation_test.go
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package api
+
+import (
+	"testing"
+	"time"
+
+	"github.com/vynulldev/vynull/library"
+)
+
+// An import stores keys as Camelot, but rekordbox key rules carry the names
+// rekordbox showed: "key is Am" must still find a track stored as 8A, and a
+// rule in either notation must find a key stored in the other.
+func TestSmartKeyRulesAcrossNotations(t *testing.T) {
+	match := func(op int, left, key string) bool {
+		tr := &library.Track{ID: 1, Key: key}
+		if op == 0 { // Vynull's own "is compatible with", which rekordbox lacks
+			return (&SmartRules{Combinator: "all", Conditions: []SmartCond{
+				{Field: "key", Operator: "compatible", Value: left}}}).Match(tr, nil, time.Now())
+		}
+		rules, _, _ := smartRulesFromRekordbox(&library.RBSmartList{Logical: 1,
+			Conditions: []library.RBSmartCond{{Property: "key", Operator: op, Left: left}}})
+		return rules.Match(tr, nil, time.Now())
+	}
+	for _, tc := range []struct {
+		op        int
+		left, key string
+		want      bool
+	}{
+		{1, "Am", "8A", true},  // is
+		{1, "8A", "Am", true},  // is, the other way round
+		{1, "Abm", "1A", true}, // an enharmonic spelling
+		{1, "Am", "8B", false}, // a different key
+		{2, "Am", "8A", false}, // is not
+		{2, "Am", "9A", true},
+		{8, "m", "8A", true}, // contains, against the classic name Am
+		{9, "m", "8B", true}, // does not contain: C has no m in either name
+		{9, "m", "8A", false},
+		{10, "8", "8A", true},       // starts with, in Camelot
+		{1, " Am", "8A", false},     // text with spaces is not a key name
+		{1, "Alpha", "Alpha", true}, // non-key text compares as text
+		{0, "Am", "9A", true},       // compatible (a neighbour), typed in classic
+		{0, "Am", "3B", false},
+	} {
+		if got := match(tc.op, tc.left, tc.key); got != tc.want {
+			t.Errorf("op %d %q vs key %q = %v, want %v", tc.op, tc.left, tc.key, got, tc.want)
+		}
+	}
+}
diff --git a/api/smart_playlist.go b/api/smart_playlist.go
index 70cc297..9cef37f 100644
--- a/api/smart_playlist.go
+++ b/api/smart_playlist.go
@@ -10,6 +10,7 @@ import (
 	"time"
 	"unicode"
 
+	"github.com/vynulldev/vynull/analysis"
 	"github.com/vynulldev/vynull/library"
 )
 
@@ -226,18 +227,69 @@ func keyMatch(op string, value any, trackKey string) bool {
 		return false
 	}
 	switch op {
-	case "is", "eq", "=", "is_not", "ne", "!=":
-		// Equality compares the key's name like any other text.
-		return stringMatch(op, value, trackKey)
+	case "is", "eq", "=":
+		return sameKey(target, trackKey)
+	case "is_not", "ne", "!=":
+		return !sameKey(target, trackKey)
 	case "compatible":
-		return camelotCompatible(trackKey, target)
-	case "contains", "not_contains", "starts_with", "ends_with":
-		// Text operators compare the key's name, as rekordbox does.
-		return stringMatch(op, value, trackKey)
+		return camelotCompatible(camelotName(trackKey), camelotName(target))
+	case "contains", "starts_with", "ends_with":
+		// Text operators compare the key's name, as rekordbox does, in
+		// either notation: an import stores keys as Camelot, but the rule
+		// may be written against rekordbox's classic names.
+		for _, name := range keyNames(trackKey) {
+			if stringMatch(op, value, name) {
+				return true
+			}
+		}
+		return false
+	case "not_contains":
+		for _, name := range keyNames(trackKey) {
+			if !stringMatch(op, value, name) {
+				return false
+			}
+		}
+		return true
 	}
 	return false
 }
 
+// sameKey reports whether a key rule's value names the track's key. It
+// compares the names as text, as rekordbox does, and also as keys in either
+// notation, since an import stores keys as Camelot ("8A") while rekordbox
+// rules carry the names rekordbox showed ("Am").
+func sameKey(rule, trackKey string) bool {
+	if stringMatch("is", rule, trackKey) {
+		return true
+	}
+	a, _ := analysis.KeyNamesFrom(rule)
+	b, _ := analysis.KeyNamesFrom(trackKey)
+	return a != "" && a == b && rule == strings.TrimSpace(rule)
+}
+
+// camelotName is a key's Camelot name when it names a key in either
+// notation ("Am" is 8A), else the text unchanged.
+func camelotName(key string) string {
+	if cam, _ := analysis.KeyNamesFrom(key); cam != "" {
+		return cam
+	}
+	return key
+}
+
+// keyNames is a track key's name in each notation it has: the stored name
+// and, for a recognised key, its Camelot and classic names.
+func keyNames(key string) []string {
+	names := []string{key}
+	if cam, std := analysis.KeyNamesFrom(key); cam != "" {
+		for _, n := range []string{cam, std} {
+			if n != key {
+				names = append(names, n)
+			}
+		}
+	}
+	return names
+}
+
 // foldText prepares text for comparison the way rekordbox's smart playlists
 // compare it (link-spec conformance smart text suites): case-insensitive, a
 // precomposed accented letter equals its base letter ("Álpha" is "alpha"),
diff --git a/api/web/index.html b/api/web/index.html
index f6ac8cc..9e06c84 100644
--- a/api/web/index.html
+++ b/api/web/index.html
@@ -11140,13 +11140,17 @@ <h4>RELATED <span class="count" id="related-count"></span></h4>
   number: [['eq','equals'], ['ne','is not'], ['lt','<'], ['lte','≤'], ['gt','>'], ['gte','≥'], ['between','between']],
   string: [['is','equals'], ['is_not','is not'], ['contains','contains'], ['not_contains','doesn’t contain'],
            ['starts_with','starts with'], ['ends_with','ends with'], ['is_empty','is empty'], ['not_empty','not empty']],
-  key:    [['is','equals'], ['is_not','is not'], ['compatible','is compatible with']],
+  // rekordbox's key operators, plus Vynull's harmonic-mixing match.
+  key:    [['is','equals'], ['is_not','is not'], ['contains','contains'], ['not_contains','doesn’t contain'],
+           ['starts_with','starts with'], ['ends_with','ends with'], ['compatible','is compatible with']],
   tag:    [['has','has tag'], ['not_has','doesn’t have tag'], ['has_any','has any tag'], ['none','has no tags']],
   date:   [['in_last_days','in the last (days)'], ['not_in_last_days','not in the last (days)'],
            ['in_last_months','in the last (months)'], ['not_in_last_months','not in the last (months)'],
            ['on','is'], ['not_on','is not'], ['before','before'], ['after','after'], ['between','between']],
   color:  [['eq','is'], ['ne','is not']],
 };
+// Key operators that test the key's name as text, so take a typed value.
+const SMART_KEY_TEXT_OPS = ['contains', 'not_contains', 'starts_with', 'ends_with'];
 // Date operators whose value is a count of days or months, not a date.
 const SMART_DATE_COUNT_OPS = ['in_last_days', 'not_in_last_days', 'in_last_months', 'not_in_last_months'];
 // Camelot key list for key field dropdowns.
@@ -11311,10 +11315,23 @@ <h4>RELATED <span class="count" id="related-count"></span></h4>
     }
     return `<input type="number" data-sm-val value="${v}" style="width:100px">`;
   }
+  if (meta.type === 'key' && SMART_KEY_TEXT_OPS.includes(op)) {
+    return `<input type="text" data-sm-val value="${escape(c.value || '')}" style="min-width:100px">`;
+  }
   if (meta.type === 'key') {
-    return `<select data-sm-val>${SMART_KEYS.map(k =>
-      `<option value="${k}" ${k === c.value ? 'selected' : ''}>${k}</option>`
-    ).join('')}</select>`;
+    // An imported rekordbox rule may name its key in classic notation
+    // ("Am"); keep that value as its own option so opening the editor never
+    // swaps the rule's key for the first one listed.
+    const v = c.value == null ? '' : String(c.value);
+    // Each key is stored in Camelot and labelled in both notations, led by
+    // the user's key display setting ("8A · Am" or "Am · 8A").
+    const opts = SMART_KEYS.map(k =>
+      `<option value="${k}" ${k === v ? 'selected' : ''}>${escape(keyBoth(k))}</option>`);
+    if (v && !SMART_KEYS.includes(v)) {
+      const p = KEY_PAIRS[v.trim().toUpperCase()];
+      opts.unshift(`<option value="${escape(v)}" selected>${escape(v)}${p ? ' · ' + p[0] : ''}</option>`);
+    }
+    return `<select data-sm-val>${opts.join('')}</select>`;
   }
   if (meta.type === 'tag') {
     const tags = (allTagsCache || []);
@@ -11601,10 +11618,24 @@ <h4>RELATED <span class="count" id="related-count"></span></h4>
     return false;
   }
   if (meta.type === 'key') {
-    const trackKey = (t.key || '').toUpperCase();
-    const target = (v || '').toString().toUpperCase();
+    // Compare keys in either notation, as the server does.
+    const cam = x => { const k = String(x || '').toUpperCase(); return (KEY_PAIRS[k] || [k])[0]; };
+    const trackKey = cam(t.key);
+    const target = cam(v);
     if (op === 'is') return trackKey === target;
     if (op === 'is_not') return trackKey !== target;
+    if (SMART_KEY_TEXT_OPS.includes(op)) {
+      // The key's name in each notation, as the server tests it.
+      const raw = String(t.key || '');
+      const p = KEY_PAIRS[raw.trim().toUpperCase()];
+      const names = (p ? [raw, p[0], p[1]] : [raw]).map(n => n.toLowerCase());
+      const q = String(v || '').toLowerCase();
+      const hit = f => names.some(f);
+      if (op === 'contains') return hit(n => n.includes(q));
+      if (op === 'not_contains') return raw !== '' && !hit(n => n.includes(q));
+      if (op === 'starts_with') return hit(n => n.startsWith(q));
+      if (op === 'ends_with') return hit(n => n.endsWith(q));
+    }
     // compatible — quick approximation; server does the authoritative check
     return trackKey === target;
   }