If you want to dynamically change the default MusicOnHold class during the call flow, follow below instructions:
- Create your custom moh class and add your audio files
![](http://helpdesk.xcallyusa.com/wp-content/uploads/2019/10/1-28-1024x558.png)
- Create variable CHANNEL(musicclass)
Please refer here to create a Variable
![](http://helpdesk.xcallyusa.com/wp-content/uploads/2019/10/2-23.png)
- Update MOH class on runtime
If you use Internal/Inbound dialplan, you need to add the Set application with following syntax
![](http://helpdesk.xcallyusa.com/wp-content/uploads/2019/10/3-22.png)
b. If you use CallySquare project, you need to add the Set block with following syntax
![](http://helpdesk.xcallyusa.com/wp-content/uploads/2019/10/4-21.png)