On 1968's seminal Astral Weeks, a twentysomething Van Morrison can be found belting his gospelly, bluesy vocals in just as fine a form as he would be 20 years hence. In the sociopolitical context of the times, the album cried out about such ubiquitous 1960s themes as cultural oppression and social upheaval. But it is Morrison's vocal dexterity and passion that maintains such timeless appeal. Take tracks like Madame George or Cyprus Avenue and you'll find such beautiful mourning, it'll be clear why Sinéad O'Connor once publicly exclaimed: "Van Morrison should be friggin' canonized".