A recent news article demonstrated how video games are fast becoming an international platform for musicians to showcase their work. If your library is using free software like Game Maker or the RPG Toolkit to develop games with teens, consider partnering them up with teen artists to develop the soundtrack.
Teens have access to a number of resources to help them understand where video game music comes from and what makes it successful. For starters, this Wikipedia article, this Gamespot feature, and this episode of NPR’s All Things Considered can provide a great introduction.
Teens can also get inspiration from visiting the websites of individual video game composers, to get a sample of their current work, or in books such as G.W. Childs’s Creating Music and Sound for Games (available through ILL) or Les Pardew’s Game Design for Teens.
As far as making the music and sounds themselves, introductory guides are available on YALSA’s Teen Tech Week page.
Carnegie Library of Pittsburgh – Teen