Marillion are a British rock group. Formed in Aylesbury, Buckinghamshire, England in 1979, their recorded studio output comprises fifteen albums and is generally regarded as comprising two distinct eras, delineated by the departure of original vocalist & frontman Fish in late 1988 after their first four albums, and the subsequent arrival of replacement Steve Hogarth ("h") in early 1989. Marillion has thus far released eleven albums with Hogarth. The core lineup of Steve Rothery (Lead Guitar and the sole 'pre-Fish' original member), Pete Trewavas (Bass), Mark Kelly (Keyboards) and Ian Mosley (Drums) is unchanged since 1984. The band has enjoyed critical and commercial success with a string of UK Top Ten hits spanning their career, an estimated fifteen million total worldwide album sales and even an entry into the Guinness Book of World Records. The band's music has changed stylistically throughout their career. The band themselves have stated that each new album tends to represent a reaction to the preceding one, and for this reason their output is difficult to 'pigeonhole'.