Instruct: Classify the given review as either positive or negative.
Query: Timeless Pink Floyd

After making the excellent but muddy "Meddle", Pink Floyd finally acquired the professional engineering and musicla discipline to produce this defining album.One of the great albums of later 20th century music, and certainly one of the most popular, "Dark Side of the Moon" produced music that just resists being imitated by other artists.Part of what makes "Dark Side" different beyond the spacey experimental style of the music is its themes on life. And the experimental style is really a bit of a cover, inside these songs are some fairly straightforward folk strains of english music."Dark Side" has a sound and style that is a knotch beyond most popular music. This is an album that will last a lifetime.