As of October 2023, there is no widely recognized artist by the name of Bruno Kiefer in the music industry. It is possible that you may be referring to a lesser-known artist or an emerging musician not yet documented in mainstream music history. If you have any additional context or details about Bruno Kiefer, such as specific songs, albums, or collaborations, please provide that information, and I would be happy to assist you further. Otherwise, if you meant another artist, feel free to clarify, and I can provide information about them.