In 2005, they released Big Money, a collection of singles, remasters, and rarities.

Stylistically, the Headquarters album shows it to be influenced by the music of Steely Dan, with arranged horns and background vocals throughout.

"[3] Also, some guitar work comes from guest artists Drew Zingg (who is best known for his work with Boz Scaggs and Steely Dan), as well as from Kim Mitchell and Rik Emmett (founder of the band Triumph).

Also making contributions on this album are Steely Dan trumpet player and musical director Michael Leonhart, with Julie Crochetière and David Blamires adding backup vocals.

[4] Headquarters has generated increasing attention and multi-genre airplay for Monkey House, with a growing international audience.