Marcus Siepen is a German musician best known as the guitarist for the heavy metal band Blind Guardian. He joined the band in 1986 and has contributed to their distinctive sound, which blends fantasy themes with complex musical arrangements. Siepen is recognized for his skillful guitar work and vocal harmonies, enhancing the band's live performances. In addition to his work with Blind Guardian, Siepen has been involved in various side projects and collaborations within the metal genre. He is also known for his passion for music education, often sharing his knowledge and experience with aspiring musicians through workshops and interviews.