There are several (at least 3) artists by that name.
1) ... is a gothic metal band from The Netherlands (www.autumn-band.com).
2) ... is a gothic rock band from US (http://www.autumn-us.com).
3) ...is a doom metal band from Russia (http://home.ural.ru/~autumn/main.htm).
1) It has a quite different sound than other gothic metal bands, because of their lead singer, Nienke de Jong. Her voice is much lower than common in this genre.
This Clip was made during the european tour with Within Temptation,the clip was filmed and editted by members of the dutch band Smogus.