There are three known artists with this name: 1) Diorama is a darkwave / electrogoth band from Germany,
2) Diorama is a folk-rock band from Italy.
3) Diorama is a post-rock/math rock band from Peru. 1) Germany (1996-present) Diorama was formed by Torben Wendt. Torben’s music was soon recognized by Adrian Hates of Diary of Dreams, so with his support and the support of Rainer Assmann (Daf/ Fad Gadget), a debut-album “Pale” was released in 1999. It was received very well both by the critics and the audience (more details further down under 1 on the wiki).

Read more about Diorama on Last.fm.