Let “piece” mean a song, work of art, collection of words, or other product.
Let “maker” mean the artist, author, designer, band, or creator of the piece.
Let “maker’s identity” mean the stage name or the real or fake persona put forward by the maker outside of the piece itself.
Let “maker’s assumed identity” mean the maker’s identity as suggested in the piece any time it is not identical to the maker’s identity.