diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index 2bdfc32..abe0b2c 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -440,7 +440,7 @@ const WaveformLane = ({
     ctx.lineWidth = 1;
     const beatDuration = (60.0 / (parseFloat(bpm) || 120));
     const barDuration = beatDuration * 4;
-    const PADDING_LEFT = beatDuration; // 1-beat margin on left
+    const PADDING_LEFT = barDuration; // 1-bar margin on left
     const tStart = scrollLeftVal / zoom - PADDING_LEFT;
     const tEnd = (scrollLeftVal + drawWidth) / zoom;
     let gridSpacing = 1.0;
@@ -1218,7 +1218,7 @@ const TempoTrackLane = ({
     ctx.fillRect(0, 0, drawWidth, height);
     const beatDuration = 60 / bpm;
     const barDuration = beatDuration * 4;
-    const PADDING_LEFT = 2; // seconds of empty space on left edge
+    const PADDING_LEFT = barDuration; // 1-bar margin on left
     const tStart = scrollLeftVal / zoom - PADDING_LEFT;
     const tEnd = (scrollLeftVal + drawWidth) / zoom;
     const firstBeat = Math.floor(tStart / beatDuration) * beatDuration;