Lead Singer Syndrome is about writing songs that are intertwining melodies (aka counterpoint) as opposed to just lots of chord changes. In the Baroque style of classical music, such as the works of Bach or Vivaldi, each instrument played a melody that complemented the others instead of simply supporting a singer or a lead instrument.
They have taken this concept and incorporated it into different styles of music - classical, funk, latin, heavy metal.
Although it is not a hard formula they force themselves to adhere to, it is a philosophy that helps them create interesting instrumental music.
Their first album is Representative Samples. Lead Singer Syndrome divided the population of musical genres into strata, then took a random sample from each stratum to produce this album.