Mp3 Tags

I am a volunteer for the Library of Congress, and have downloaded several National Jukebox as mp3s. All of them save one have lacked "mp3 tags" (data included within the mp3 file), such as artist, year, and song cover(the photo of the gramophone record). I have manually added such information for the songs I have downloaded and was wondering if there was any way to update the mp3 track on the library of congress website.