diff --git a/js/moleculesandlight/view/LightSpectrumDialog.js b/js/moleculesandlight/view/LightSpectrumDialog.js
index ab8dbc39..93762b17 100644
--- a/js/moleculesandlight/view/LightSpectrumDialog.js
+++ b/js/moleculesandlight/view/LightSpectrumDialog.js
@@ -18,10 +18,6 @@ define( require => {
   const Dialog = require( 'SUN/Dialog' );
   const inherit = require( 'PHET_CORE/inherit' );
   const moleculesAndLight = require( 'MOLECULES_AND_LIGHT/moleculesAndLight' );
-  const MoleculesAndLightA11yStrings = require( 'MOLECULES_AND_LIGHT/common/MoleculesAndLightA11yStrings' );
-
-  // a11y string
-  const spectrumWindowDescriptionString = MoleculesAndLightA11yStrings.spectrumWindowDescriptionString.value;
 
   /**
    * @constructor
@@ -34,11 +30,7 @@ define( require => {
 
       // phet-io
       tandem: tandem,
-      phetioDynamicElement: true,
-
-      // a11y
-      tagName: 'p',
-      descriptionContent: spectrumWindowDescriptionString
+      phetioDynamicElement: true
     } );
   }
 
diff --git a/js/moleculesandlight/view/SpectrumDiagram.js b/js/moleculesandlight/view/SpectrumDiagram.js
index e7618606..a32b141c 100644
--- a/js/moleculesandlight/view/SpectrumDiagram.js
+++ b/js/moleculesandlight/view/SpectrumDiagram.js
@@ -28,6 +28,7 @@ define( require => {
   const Util = require( 'DOT/Util' );
   const Vector2 = require( 'DOT/Vector2' );
   const WavelengthSpectrumNode = require( 'SCENERY_PHET/WavelengthSpectrumNode' );
+  const MoleculesAndLightA11yStrings = require( 'MOLECULES_AND_LIGHT/common/MoleculesAndLightA11yStrings' );
 
   // strings
   const spectrumWindowCyclesPerSecondUnitsString = require( 'string!MOLECULES_AND_LIGHT/SpectrumWindow.cyclesPerSecondUnits' );
@@ -43,6 +44,9 @@ define( require => {
   const spectrumWindowWavelengthArrowLabelString = require( 'string!MOLECULES_AND_LIGHT/SpectrumWindow.wavelengthArrowLabel' );
   const spectrumWindowXrayBandLabelString = require( 'string!MOLECULES_AND_LIGHT/SpectrumWindow.xrayBandLabel' );
 
+  // PDOM strings
+  const spectrumDialogDescriptionString = MoleculesAndLightA11yStrings.spectrumDialogDescriptionString.value;
+
   // shared constants
   const LABEL_FONT = new PhetFont( 16 );
   const SUBSECTION_WIDTH = 490; // width of each subsection on the window (arrows, chirp node, and labeled diagram).
@@ -108,7 +112,19 @@ define( require => {
     const decreasingWavelengthNode = new ChirpNode();
     children.push( decreasingWavelengthNode );
 
-    LayoutBox.call( this, { orientation: 'vertical', children: children, spacing: 15 } );
+    LayoutBox.call( this, {
+      orientation: 'vertical',
+      children: children,
+      spacing: 15,
+
+      // PDOM
+      containerTagName: 'div',
+      tagName: 'h1',
+      innerContent: spectrumWindowTitleString,
+      descriptionTagName: 'p',
+      descriptionContent: spectrumDialogDescriptionString,
+      appendDescription: true
+    } );
   }
 
   moleculesAndLight.register( 'SpectrumDiagram', SpectrumDiagram );