Hi there and welcome
By default they go to your downloads folder. Go to your Apps, then open the app My Files.
There look in the downloads folder for these.
Else check in the folder that has the same name as the app you used for downloading
The default download location will depend on which app you use for downloading the MP3.
Check in the settings of the App for this. If it is not an option, then it can only go to either the downloads folder or the folder with the same name as the App as this will be hard coded in the app itself.
If you have continued problems, or would like any additional information or assistance, please do not hesitate to let me know.
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