diff --git a/app.js b/app.js
index 3c4d93d..b2c54ca 100644
--- a/app.js
+++ b/app.js
@@ -1589,7 +1589,7 @@ $('btn-refs-csv-import').addEventListener('click', async () => {
     await loadAll();
     let html = `<p class="csv-ok">✓ ${results.created} reference${results.created !== 1 ? 's' : ''} imported.</p>`;
     if (results.warnings.length) {
-      html += `<p class="csv-error">${results.warnings.length} skipped — tune not found:</p><ul class="csv-errors">`;
+      html += `<p class="csv-error">${results.warnings.length} skipped:</p><ul class="csv-errors">`;
       results.warnings.forEach(w => { html += `<li>${esc(w)}</li>`; });
       html += '</ul>';
     }
@@ -1633,13 +1633,29 @@ async function importRefsCsvRows(rows) {
   }
 
   for (const row of rows) {
-    const tuneName = row.tune_name?.trim();
+    const tuneName   = row.tune_name?.trim();
+    const sourceName = row.source?.trim();
     if (!tuneName) continue;
 
-    const tune = allTunes.find(t => (t.name ?? '').toLowerCase() === tuneName.toLowerCase());
-    if (!tune) {
-      results.warnings.push(tuneName);
+    const matches = allTunes.filter(t => (t.name ?? '').toLowerCase() === tuneName.toLowerCase());
+    let tune;
+    if (matches.length === 0) {
+      results.warnings.push(`${tuneName} — not found`);
       continue;
+    } else if (matches.length === 1) {
+      tune = matches[0];
+    } else {
+      // Multiple tunes with this name — need source to disambiguate
+      if (sourceName) {
+        tune = matches.find(t => (t.source?.name ?? '').toLowerCase() === sourceName.toLowerCase());
+        if (!tune) {
+          results.warnings.push(`${tuneName} (source: ${sourceName}) — no matching source found`);
+          continue;
+        }
+      } else {
+        results.warnings.push(`${tuneName} — ambiguous (${matches.length} tunes with this name; add a source column to disambiguate)`);
+        continue;
+      }
     }
 
     try {
diff --git a/index.html b/index.html
index 8a0bbc3..3e87558 100644
--- a/index.html
+++ b/index.html
@@ -266,6 +266,7 @@
         <thead><tr><th>Column</th><th>Required</th><th>Notes</th></tr></thead>
         <tbody>
           <tr><td>tune_name</td><td>Yes</td><td>Must match an existing tune (case-insensitive)</td></tr>
+          <tr><td>source</td><td></td><td>Disambiguates when multiple tunes share a name</td></tr>
           <tr><td>link</td><td></td><td>URL</td></tr>
           <tr><td>site</td><td></td><td>Site name — created if new</td></tr>
           <tr><td>musician1</td><td></td><td>Musician name — created if new</td></tr>