diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index 856a2ab..17ef12b 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -5739,29 +5739,32 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, onClose, onUpdateNot
         }
         return;
       }
-      rulerDragRef.current = { startX: e.clientX, startBeat: clickBeat, scrollLeft: e.currentTarget.scrollLeft };
-    },
-    onMouseMove: e => {
-      if (!rulerDragRef.current) return;
-      const rect = e.currentTarget.getBoundingClientRect();
-      const x = e.clientX - rect.left + rulerDragRef.current.scrollLeft;
-      const beat = Math.max(0, x / pixelsPerBeat);
-      if (Math.abs(e.clientX - rulerDragRef.current.startX) > 5) {
-        const sBeat = Math.max(0, Math.min(rulerDragRef.current.startBeat, beat));
-        const eBeat = Math.max(sBeat + 1, Math.max(rulerDragRef.current.startBeat, beat));
-        setLoopStartBeat(sBeat);
-        setLoopEndBeat(eBeat);
-        setIsLooping(true);
-        setSubTabs(prev => prev.map(s => s.id === st.id ? {
-          ...s,
-          selectionStart: sBeat * beatSec,
-          selectionEnd: eBeat * beatSec,
-          isLooping: true
-        } : s));
-      }
-    },
-    onMouseUp: () => { rulerDragRef.current = null; },
-    onMouseLeave: () => { rulerDragRef.current = null; }
+      const startData = { startX: e.clientX, startBeat: clickBeat, scrollLeft: e.currentTarget.scrollLeft };
+      rulerDragRef.current = startData;
+      const onMove = (ev) => {
+        const r = rulerScrollRef.current;
+        if (!r || !rulerDragRef.current) return;
+        const rRect = r.getBoundingClientRect();
+        const bx = ev.clientX - rRect.left + rulerDragRef.current.scrollLeft;
+        const beat = Math.max(0, bx / pixelsPerBeat);
+        if (Math.abs(ev.clientX - rulerDragRef.current.startX) > 5) {
+          const sBeat = Math.max(0, Math.min(rulerDragRef.current.startBeat, beat));
+          const eBeat = Math.max(sBeat + 1, Math.max(rulerDragRef.current.startBeat, beat));
+          setLoopStartBeat(sBeat);
+          setLoopEndBeat(eBeat);
+          setIsLooping(true);
+          setSubTabs(prev => prev.map(s => s.id === st.id ? {
+            ...s,
+            selectionStart: sBeat * beatSec,
+            selectionEnd: eBeat * beatSec,
+            isLooping: true
+          } : s));
+        }
+      };
+      const onUp = () => { rulerDragRef.current = null; document.removeEventListener('mousemove', onMove); document.removeEventListener('mouseup', onUp); };
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    }
   }, /*#__PURE__*/React.createElement("div", {
     style: {
       width: `${viewWidth}px`,
@@ -5774,7 +5777,65 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, onClose, onUpdateNot
       width: `${(loopEndBeat - loopStartBeat) * pixelsPerBeat}px`,
       top: 0, bottom: 0
     },
-    className: "absolute bg-emerald-500/15 border-l border-r border-emerald-400 pointer-events-none"
+    className: "absolute bg-emerald-500/15 border-l border-r border-emerald-400"
+  }, /*#__PURE__*/React.createElement("div", {
+    style: { position: 'absolute', left: 0, top: 0, bottom: 0, width: '4px', cursor: 'ew-resize' },
+    onMouseDown: (e) => {
+      e.stopPropagation();
+      const startBeat = loopStartBeat;
+      const onMove = (ev) => {
+        const r = rulerScrollRef.current;
+        if (!r) return;
+        const rRect = r.getBoundingClientRect();
+        const bx = ev.clientX - rRect.left + r.scrollLeft;
+        const nBeat = Math.max(0, Math.min(loopEndBeat - 1, Math.round(bx / pixelsPerBeat / 4) * 4));
+        setLoopStartBeat(nBeat);
+        setSubTabs(prev => prev.map(s => s.id === st.id ? { ...s, selectionStart: nBeat * beatSec } : s));
+      };
+      const onUp = () => { document.removeEventListener('mousemove', onMove); document.removeEventListener('mouseup', onUp); };
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    }
+  }), /*#__PURE__*/React.createElement("div", {
+    style: { position: 'absolute', right: 0, top: 0, bottom: 0, width: '4px', cursor: 'ew-resize' },
+    onMouseDown: (e) => {
+      e.stopPropagation();
+      const onMove = (ev) => {
+        const r = rulerScrollRef.current;
+        if (!r) return;
+        const rRect = r.getBoundingClientRect();
+        const bx = ev.clientX - rRect.left + r.scrollLeft;
+        const nBeat = Math.max(loopStartBeat + 1, Math.round(bx / pixelsPerBeat / 4) * 4);
+        setLoopEndBeat(nBeat);
+        setSubTabs(prev => prev.map(s => s.id === st.id ? { ...s, selectionEnd: nBeat * beatSec } : s));
+      };
+      const onUp = () => { document.removeEventListener('mousemove', onMove); document.removeEventListener('mouseup', onUp); };
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    }
+  }), /*#__PURE__*/React.createElement("div", {
+    style: { position: 'absolute', left: '4px', right: '4px', top: 0, bottom: 0, cursor: 'grab' },
+    onMouseDown: (e) => {
+      e.stopPropagation();
+      const startBeat = loopStartBeat;
+      const range = loopEndBeat - loopStartBeat;
+      const offsetBeat = startBeat + range / 2;
+      const onMove = (ev) => {
+        const r = rulerScrollRef.current;
+        if (!r) return;
+        const rRect = r.getBoundingClientRect();
+        const bx = ev.clientX - rRect.left + r.scrollLeft;
+        const centerBeat = Math.round(bx / pixelsPerBeat / 4) * 4;
+        const halfRange = range / 2;
+        const newStart = Math.max(0, centerBeat - halfRange);
+        setLoopStartBeat(newStart);
+        setLoopEndBeat(newStart + range);
+        setSubTabs(prev => prev.map(s => s.id === st.id ? { ...s, selectionStart: newStart * beatSec, selectionEnd: (newStart + range) * beatSec } : s));
+      };
+      const onUp = () => { document.removeEventListener('mousemove', onMove); document.removeEventListener('mouseup', onUp); };
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    }
   })))), /*#__PURE__*/React.createElement("div", {
     className: "flex-1 flex overflow-hidden min-h-0 relative"
   }, /*#__PURE__*/React.createElement("div", {
@@ -5803,6 +5864,13 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, onClose, onUpdateNot
     onMouseLeave: handleGridMouseUp,
     onContextMenu: handleContextMenu,
     className: "absolute inset-0 cursor-crosshair"
+  }), loopStartBeat !== null && loopEndBeat !== null && loopEndBeat > loopStartBeat && /*#__PURE__*/React.createElement("div", {
+    style: {
+      left: `${loopStartBeat * pixelsPerBeat}px`,
+      width: `${(loopEndBeat - loopStartBeat) * pixelsPerBeat}px`,
+      top: 0, bottom: 0
+    },
+    className: "absolute bg-emerald-500/10 border-l border-r border-emerald-400/50 pointer-events-none"
   })))), showCC && /*#__PURE__*/React.createElement("div", {
     style: { height: `${ccHeight}px` },
     className: "bg-[#161616] border-t border-zinc-900 flex shrink-0 relative"
@@ -5835,6 +5903,13 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, onClose, onUpdateNot
     onMouseUp: () => { ccDragRef.current = null; },
     onMouseLeave: () => { ccDragRef.current = null; },
     className: "absolute inset-0"
+  }), loopStartBeat !== null && loopEndBeat !== null && loopEndBeat > loopStartBeat && /*#__PURE__*/React.createElement("div", {
+    style: {
+      left: `${loopStartBeat * pixelsPerBeat}px`,
+      width: `${(loopEndBeat - loopStartBeat) * pixelsPerBeat}px`,
+      top: 0, bottom: 0
+    },
+    className: "absolute bg-emerald-500/10 border-l border-r border-emerald-400/50 pointer-events-none"
   })))), scaleMenuPos && renderScaleContextMenu());
 };
 
@@ -9304,7 +9379,7 @@ const App = () => {
           const end = (n.start_beat || 0) + (n.duration_beats || 1);
           if (end > maxEnd) maxEnd = end;
         });
-        return maxEnd * beatSec + 1.0;
+        return Math.max(maxEnd * beatSec, 16 * beatSec * 4) + 1.0;
       })() : st.buffer.duration;
       if (bufferPos >= effectiveDuration) {
         stopAllPlayback();