Billy Keen is not recognized as a notable figure in the world of music, according to available historical records and musical databases. This could possibly be due to a misspelling, a less-known or emerging artist, or a local or niche performer. As a result, detailed information about the musical style, historical significance, or influential works of an artist named "Billy Keen" cannot be provided at this time. It's recommended to double-check the spelling or provide additional context to identify the correct artist.