Replace obnoxious cowbell with gentle bell tone as default hold music

## Default Music Improvement
- Changed from Twilio's annoying cowbell.mp3 to gentle bell-ringing-05.wav
- Much more pleasant and professional sounding default
- Updated both settings default and code fallback

## Better Music Suggestions
- Added comprehensive list of recommended music sources in admin interface
- Suggested alternatives: WordPress Media Library, Freesound.org, Archive.org, Incompetech.com, Zapsplat.com
- Provided guidance for different business types and use cases

## User Experience
- No more jarring cowbell sounds for new installations
- Clear instructions on how to customize with better alternatives
- Emphasis on using WordPress Media Library for reliability

The new default provides a much more professional audio experience while still maintaining functionality for users who haven't customized their hold music yet.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

admin/class-twp-admin.php

@@ -404,9 +404,17 @@ class TWP_Admin {
                         <th scope="row">Default Queue Music URL</th>
                         <td>
                             <input type="url" name="twp_default_queue_music_url" 
-                                   value="<?php echo esc_attr(get_option('twp_default_queue_music_url', 'https://api.twilio.com/cowbell.mp3')); ?>" 
+                                   value="<?php echo esc_attr(get_option('twp_default_queue_music_url', 'https://www.soundjay.com/misc/sounds/bell-ringing-05.wav')); ?>" 
                                    class="regular-text" />
                             <p class="description">Default music for queue wait times and call hold when no specific music is set. Must be publicly accessible MP3 or WAV file.</p>
+                            <p class="description"><strong>Default:</strong> Gentle bell tone (much better than cowbell!). <strong>Better alternatives:</strong></p>
+                            <ul class="description">
+                                <li>• Upload your own music to WordPress Media Library and use that URL</li>
+                                <li>• <strong>Freesound.org</strong> - Free royalty-free music and sounds</li>
+                                <li>• <strong>Archive.org</strong> - Public domain classical music</li>
+                                <li>• <strong>Incompetech.com</strong> - Kevin MacLeod's royalty-free music</li>
+                                <li>• <strong>Zapsplat.com</strong> - Professional hold music (free account required)</li>
+                            </ul>
                         </td>
                     </tr>
                     
@@ -6939,7 +6947,7 @@ class TWP_Admin {
                 $hold_music_url = get_option('twp_hold_music_url', '');
                 if (empty($hold_music_url)) {
                     // Fall back to default queue music if no hold music is set
-                    $hold_music_url = get_option('twp_default_queue_music_url', 'https://api.twilio.com/cowbell.mp3');
+                    $hold_music_url = get_option('twp_default_queue_music_url', 'https://www.soundjay.com/misc/sounds/bell-ringing-05.wav');
                 }
                 
                 $twiml = new \Twilio\TwiML\VoiceResponse();