Songs in the Key of X: Music from and Inspired by the X-Files was the first album released in association with the popular television series The X-Files released in 1996. It contained both music that had been featured in the show, as well as music whose themes were in line with the concepts of the show. The album peaked at #47 on Billbord's Top 200 chart. Producers used the Compact Disc's pregap, so a listener would have to actually manually rewind the first track a full nine minutes to hear the 2 hidden tracks by Nick Cave. This is hinted at in the CD booklet - "Nick Cave and the Dirty Three would like you to know that "0" is also a number." Not all CD or DVD players will allow you to "rewind" back to these tracks as this violates Red Book standards. I was tempted to put up the bonus "hidden" tracks but decided against it and will go with my faves from one of my all time favorite TV shows.
Unmarked Helicopters by Soul Coughing (featured in episode: Max)
Red Right Hand by Nick Cave and the Bad Seeds (featured in episode: Ascension)