There are three albums of music either featured in specific episodes of The X-Files or inspired by the series.
The first of these albums was The Truth and The Light, a 20-track album of Mark Snow's music, taken from various X-Files episodes, overlaid with selected dialogue from the series' first two seasons.
The second compilation, Songs in the Key of X, was also released in 1996, and featured 15 tracks by a variety of artists. The second compilation, The X-Files: The Album, was released in 1998 and featured 14 tracks by various artists (some of whom also appeared on Songs in the Key of X).
Full track listings and further information can be found on the following pages: