I accidentally misspelled a songwriter's name on iTunes library

I accidentally misspelled a songwriter's name when inputting (i.e. John Lenon instead of John Lennon). Now every time I input a songwriter that starts "John Len" both options come up, even though I have changed the individual song that was incorrect. How do I get rid of the "John Lenon" in my options when typing? Thanks.

[Re-Titled by Moderator]