Question: Who founded the Dutch Symphonic metal band who released the album Black Symphony?

Context paragraphs:
Dunwich (band): Dunwich is an Italian symphonic/gothic metal band founded in Rome in 1985.  Dunwich were among the first to use a female vocalist and symphonic music elements, especially brass instrument.  Rockeramagazine considers them forerunners of the modern symphonic metal, defining them as the "first symphonic metal band".

Black Symphony: Black Symphony is a live album, DVD and Blu-ray Disc from Dutch symphonic metal band Within Temptation.  It was released worldwide on September 22–24, 2008 and is available on 2-disc DVD, 2-disc CD, and Blu-ray.

Isaac Delahaye: Isaac Delahaye (born 9 January 1982) is a Belgian guitarist and composer, best known as the lead guitarist of Dutch symphonic metal band Epica since 2009.  Prior to that he was lead guitarist in the Dutch death metal band God Dethroned.  Delahaye replaced former guitarist Jens van der Valk in God Dethroned after van der Valk left in 2004.  He joined the band after a request from drummer and longtime friend Ariën van Weesenbeek and after several meetings with van Weesenbeek and Henri Sattler, Delahaye was welcomed into the band on 29 June 2004.  On 15 January 2009, the official announcement came that Isaac was no longer a part of God Dethroned.  Soon afterwards, an announcement came from the band Epica that proclaimed Delahaye as their recently hired guitarist.

Within Temptation: Within Temptation is a Dutch symphonic metal band founded in April 1995 by vocalist Sharon den Adel and guitarist Robert Westerholt.  They have always been classified by critics as gothic metal, although the "gothic" influence varies with each album.  Their most prominent and well-known sound is described as symphonic metal, although their earlier material, such as debut album "Enter", was mostly gothic metal.  "Enter" even had a hint of doom metal.  In an interview, Den Adel said they fell into a symphonic rock genre with various influences.  In a later interview with Dutch music platform 3VOOR12, den Adel stated that "we consider ourselves more a symphonic rock band ... in my opinion, we are no gothic band".

Tarot (album): Tarot is the sixth full-length album by the Spanish power metal band Dark Moor.  The songs of the album are all named after the Major Arcana deck in the Tarot card game.  The first single extracted from the album was "The Chariot".  Manda Ophius of the Dutch symphonic metal band Nemesea is the guest female vocalist on "Tarot". The final track, "the Moon", samples Ludwig van Beethoven's "Symphony No. 5" and "Moonlight Sonata".  The bonus track, "Mozart's March" is based on Wolfgang Amadeus Mozart's "Rondo A'la Turca".  It was also performed live in Granada, Spain, Piorno Rock, back in 2002, five years before it was even released.

Invisible Circles: Invisible Circles is the third studio album by Dutch symphonic metal band After Forever.  It was released on 25 March 2004, by the small Dutch label Transmission Records.  It is After Forever's first full-length album since the dismissal of guitarist and composer Mark Jansen, whose musical tastes had strongly influenced the sound of their first work "Prison of Desire" (2000) and their successful second offering "Decipher" (2001).  In this work After Forever choose a new musical direction, mostly revolving around elements of progressive metal instead of the gothic and symphonic metal of previous albums.  The creative process for "Invisible Circles" took more than a year and required the use of three recording studios in the Netherlands and Germany.  A long tour to support the album brought the band to some of the most important European rock festivals and to Central and South America.

King of Kings (Leaves' Eyes album): King of Kings is the sixth studio album by the German symphonic metal band Leaves' Eyes.  It contains guest appearances of a.o. Simone Simons from the Dutch symphonic metal band Epica and Lindy-Fay Hella from the Norwegian dark folk act Wardruna.  It is their last album with Liv Kristine on vocals.

Martijn Westerholt: David Martijn Westerholt (born 30 March 1979 in Waddinxveen, Netherlands) is the cofounder (along with Charlotte Wessels), keyboardist, and the main songwriter of the Dutch symphonic metal band Delain.  He was previously a member of symphonic metal band Within Temptation, until he was diagnosed with infectious mononucleosis shortly after the release of Within Temptation's second full-length studio album, "Mother Earth".  His brother Robert Westerholt is the guitarist and founder of Within Temptation.  He currently lives in Zwolle, where he resides since his study in Communication at Windesheim College in 1998.

The Classical Conspiracy: The Classical Conspiracy is the second live album released by the Dutch symphonic metal band Epica.  The recorded live show took part in Miskolc, Hungary on 14 June 2008 in the framework of the Miskolc Opera Festival, where the Swedish symphonic metal band Therion had done a similar show a year before.  Epica performed on stage with a 40-piece orchestra and a 30-piece choir, entirely composed of Hungarian musicians conducted by Zsolt Regos.  The expanded ensemble played classical music, excerpts from operas and movie soundtracks, as well as Epica's songs.  The album was released on 8 May 2009 through Nuclear Blast Records.

Hand of Sorrow: "Hand of Sorrow" is a song by the Dutch symphonic metal/rock band Within Temptation taken from their fourth album "The Heart of Everything".  The song is part of the promotion for their 2008 live DVD, "Black Symphony", according to their web page, as well as "Forgiven", which was released as a single.

Supporting paragraphs: Black Symphony Within Temptation
Answer: Sharon den Adel and guitarist Robert Westerholt