The world would be a different place without soft-rock superstar Kenny Loggins. Films like Top Gun and Footloose would want for the gutsy theme songs Loggins wrote for them, and the entire canon of so-called Yacht Rock might never have existed. Emerging in the early '70s as one half of Loggins and Messina, the songwriter went solo in '77. In addition to his own albums, Loggins co-wrote tracks like "What a Fool Believes" for Michael McDonald. His sound ranges from elegiac ballads to jaunty rock, and it's earned him countless gold and platinum albums. Plus, that beard…