OSI is an American progressive rock band, originally formed by Fates Warning guitarist Jim Matheos in 2002. Chroma Key keyboardist and vocalist Kevin Moore is the only other full-time member of the band. The collaboration may be considered a studio project, as its members and contributors write and track most of their material independently, sharing and developing tracks long-distance, only coming together at the end of the process for mixing and additional tracking.

O.S.I. (Office Of Strategic Influence) is one of several prog metal supergroup/projects that always seem to revolve around members of Dream Theater or Cynic, and in this case both bands are represented. The foundation was laid when former DT keyboardist Kevin Moore decided to collaborate with current Fates Warning guitarist Jim Matheos in a new project, and the project was completed by two more notables, that being Sean Malone (Cynic, Aghora) and Mike Portnoy (Dream Theater).

Progressive rock (often shortened to prog or prog rock) is a form of rock music that evolved in the late 1960s and early 1970s as part of a "mostly British attempt to elevate rock music to new levels of artistic credibility." The term "art rock" is often used interchangeably with "progressive rock", but while there are crossovers between the two genres, they are not identical.

Progressive rock songs often avoid common popular music song structures of verse/chorus form, and their extended lengths allow complex themes that cannot be fully developed within the span of a three-minute single. Musical forms are blurred through the use of extended sections and of musical interludes that bridge separate sections together, which results in classical-style suites.