Can a single song change the course of an artist's career?

In this episode of Tracks On Trial, we're putting two of the most extraordinary comeback stories in music history under the microscope. Roy Orbison and Tina Turner both returned from career setbacks to produce some of the most celebrated music of their lives, but whose comeback deserves the ultimate verdict?

Roy Orbison's remarkable resurgence during the late 1980s introduced a whole new generation to one of rock and roll's greatest voices. Meanwhile, Tina Turner's Private Dancer transformed her into one of the world's biggest stars after years of personal hardship and professional uncertainty.

But which comeback was the more significant? Which artist overcame the greatest obstacles? And which music has stood the test of time?

As always, t ...