diff --git a/app/javascript/mastodon/components/media_gallery.js b/app/javascript/mastodon/components/media_gallery.js
index 56618462b49fa17a4a5836e7c3383bf0381fc17e..77bac61eec9e2a20b3ff71a710af2618c8b26626 100644
--- a/app/javascript/mastodon/components/media_gallery.js
+++ b/app/javascript/mastodon/components/media_gallery.js
@@ -157,7 +157,7 @@ class Item extends React.PureComponent {
     if (attachment.get('type') === 'unknown') {
       return (
         <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
-          <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url')} target='_blank' style={{ cursor: 'pointer' }}>
+          <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url')} target='_blank' style={{ cursor: 'pointer' }} title={attachment.get('description')}>
             <canvas width={32} height={32} ref={this.setCanvasRef} className='media-gallery__preview' />
           </a>
         </div>
diff --git a/app/javascript/styles/mastodon/components.scss b/app/javascript/styles/mastodon/components.scss
index 545427d222642051eb6dc73e79f065818ca92373..4a0d64ad380e85004f33da7b675d7e49095e1113 100644
--- a/app/javascript/styles/mastodon/components.scss
+++ b/app/javascript/styles/mastodon/components.scss
@@ -557,6 +557,7 @@
 
     .compose-form__upload-thumbnail {
       border-radius: 4px;
+      background-color: $base-shadow-color;
       background-position: center;
       background-size: cover;
       background-repeat: no-repeat;
diff --git a/app/models/media_attachment.rb b/app/models/media_attachment.rb
index ae94ce68a1526b9e92f8475f2fd4af67e99d449c..4c55d4b987e686decb67e9ea9b63d8b8b4036b59 100644
--- a/app/models/media_attachment.rb
+++ b/app/models/media_attachment.rb
@@ -69,9 +69,13 @@ class MediaAttachment < ApplicationRecord
 
   AUDIO_STYLES = {
     original: {
-      format: 'ogg',
-      content_type: 'audio/ogg',
-      convert_options: {},
+      format: 'mp3',
+      content_type: 'audio/mpeg',
+      convert_options: {
+        output: {
+          'q:a' => 2,
+        },
+      },
     },
   }.freeze