The two-disc retrospective The Essential Leonard Cohen traces the Canadian bard’s musical maturity from poet and novelist who sang a little, to multidimensional artist whose oracular vocals and increasingly rich arrangements are every bit as compelling as his verse. Even when Cohen came to prominence through the 1960s songcraft of “Suzanne” and “Bird on a Wire”, the “folksinger” tag never really fit. Later highlights ranging from the deadpan drollery of “Tower of Song” and “Everybody Knows” to the apocalyptic anthemry of “First We Take Manhattan” and “Democracy” suggest that other labels might be more appropriate: cabaret surrealist, spiritual gadfly, sensual prophet, agent provocateur.