Markus H. J. Jansen is a Dutch guitarist, vocalist, and songwriter. A prominent figure in the symphonic metal subgenre, he is known for his work with the bands After Forever (1995–2002), Epica (2002–present), and MaYaN (2010–present).

Symphonic metal is a cross-generic style designation for the symphonic subsets of heavy metal music subgenres. It is used to denote any metal band that makes use of symphonic or orchestral elements. The style features the heavy drums and guitars of metal with different elements of orchestral classical music, such as symphonic instruments, choirs and sometimes a full orchestra, or just keyboard orchestration.