Hi there Jill,

Yes, you can actually change your hold music by going to Admin > Channels > Voice > Numbers tab > Edit > select a new greeting next from the drop-down menu in the Settings tab, as shown below:

Although it says in the article that its a greeting, you can actually add a file here, such as your music, as your wait/hold "greeting".

From here, you can choose what type of greeting would you like to change. Once you have selected from the options above, you will now have the option to either record your greeting or upload a file. :)

To know more about changing your voice greetings, an article can be found here: Managing outgoing greetings.

Hope this answers your question. :)