In your Account Settings, you can set default Playlist contact information. This field will populate the grouping field on all Songspace MP3s.
Note: If you're iTunes version is newer than 12.5.1, this field will populate in the iTunes work name field. For more information, click here.
To get to your Account Settings, hover over your profile image in the top right corner of your home page and click Account Settings from the dropdown menu.
To edit the default Playlist contact information field, click the pencil icon next to it.
After clicking the pencil icon, enter in the information and click the Save button.