Hi Jalen,
You cannot add a new sound directly to the Alarm app, however, there is a work around.
From Start screen, type C:Windows\Media and open the folder.
Now, we need to rename one of the Alarm file. Let's us take Alarm01.
We cannot directly rename the file(you get an access denied error). We have to provide permission to the folder.
Refer to the section from this article on how to give permission to a folder Unable to access, edit, save or delete, files and folders.
After giving the right permission, rename Alarm01, follow these steps:
a. From C:Windows\Media window, click on View tab.
b. Uncheck the option File Name Extension.
c. Rename Alarm01.wav to Alarm01.bak.
Important: Alarm app plays only .wav format files. So please convert your .wma file it to .wav format by renaming it. (Let us assume your file name was xyz.wma, so please convert it to xyz.wav)
Again, rename the xyz.wav file to Alarm01.wav. Copy the file and paste it to **C:Windows\Media.**You will now have both Alarm01.bak and Alarm01.wav in the C:\Windows\Media folder.
Open the Alarm app and from Sound category, try playing Chimes.
Hope this helps. If you have further queries, we will be happy to help.