The music for the Drakengard series, known as Drag-On Dragoon (ドラッグ オン ドラグーン, Doraggu on doragūn, commonly abbreviated as DOD) in Japan, has been handled by multiple composers since the release of the original game in 2004. Drakengard's composers were Nobuyoshi Sano and Takayuki Aihara, Drakengard 2 was handled by Ryoki Matsumoto and Aoi Yoshiki, and Drakengard 3 was composed for by Keiichi Okabe, the composer for series spin-off Nier. Sano remained as a sound director for the second game, and his music was used as a reference for the third. Multiple albums have been released for the music of the series: Drag-On Dragoon Original Soundtrack Vol.1 and Vol.2 were released on October and November 2004, while a two-disc re-release titled Drag-On Dragoon Original Soundtrack was released in April 2011. The Drag-On Dragoon 2 Original Soundtrack was released on July 20, 2005. A promotional disc with two tracks from the soundtrack was released in the same year. The official soundtrack for the third game, Drag-On Dragoon 3 Original Soundtrack, was released January 21, 2014. A compilation of chiptune remixes of the previous games and Nier, Drag-On Dragoon Chips Music, was released on December 19, 2013 as part of the Drag-On Dragoon 10 Anniversary Box.
The series has also received theme songs from multiple Japanese pop artists, all of which have been released as singles. A re-orchestration of Mika Nakashima's single "Hitori" was used as the theme for Drakengard 2, incorporating elements from the game. Two theme songs were written for Drakengard 3: "Kuroi Uta" and "This Silence is Mine". The former was sung by Eir Aoi, a fan of the series, and written by Nier writer Kikuchi Hana. The latter was specially written and sung by Onitsuka Chihiro, who created the song around the themes and characters of the game. Both songs were composed by Okabe. All three singles have been in the top 40 best-selling singles in the Japanese Oricon music charts.
The soundtracks have received mixed to positive reviews from both dedicated video game music outlets and video game critics. The first game was noted for its disturbing style, which both drew criticism for repetitiveness and praise for suiting the game's atmosphere. It has been generally cited as an experimental soundtrack. The second game's soundtrack received a more positive reception, with the general opinion being that it was a more traditional and consequently more comfortable soundtrack. The third game's soundtrack also received fairly positive comments, mainly praising its quality, although critiques were made concerning its variety. The chiptune compilation was generally liked, except for its exclusivity to the special release. The singles have also received praise.