In a six-year time span, the Beatles
released the cream of their creative output: seven albums, any of which may be considered the greatest album of the rock era.
In a six-year time span, the Rolling Stones released four albums of the grittiest, meanest, smartest and at times prettiest, most soulful music ever made.
In any given six-year time span, Bob Dylan will produce an album of mediocrity, a live album, two LPs of increasing strength, and one "masterpiece".
In a six-year time span, the Velvet Underground had an entire career that influenced the face and psyche of modern music more than any other non-platinum band, and most "superstars".
In a six-year time span, Neil Young will go through three personas, Elvis Costello will produce a quintet of albums of varying worth, disco will flourish, die, and be reborn in trendy clothing, and any group of angry young men that care to will give rock an artistic kick in the pants.
In a six-year time period, Boston, purveyors of album-rock formula and the bedrock sound of ugly American radio as we know it...Xeroxed their first album and sold it as their third.