In Buffy, Ballads, and Bad Guys Who Sing: Music in the Worlds of Joss Whedon (November 2010) Kral is described by Matthew Mills as belonging to the "Christophe Beck 'school'" with fellow composers of the Buffy/Angel shows. Beck and Kral worked closely during season 1, sometimes co-composing, while Kral continued independently for seasons 2 to 5 as Beck concentrated on Buffy and other projects. Angel finished its last season in May 2004.
In Buffy, Ballads, and Bad Guys Who Sing: Music in the Worlds of Joss Whedon (November 2010) Kral is classified by Matthew Mills as being part of a group of composers known as the "Christophe Beck approach" along with other contributors to the Buffy/Angel series. During season 1, Beck and Kral collaborated on music, sometimes co-composing, while Kral continued to work independently for seasons 2 through 5 as Beck focused on other projects. The Angel series concluded its final season in May 2004.