Robin Roberts sits down with music legend Elton John to look back at his life and career. Lady Gaga, Charlie Puth, Brandi Carlile and other artists Elton has mentored and collaborated with share what it is like working with the legendary musician.

"IMPACT x Nightline" speaks to industry insiders about the ongoing feud between A-list rappers Kendrick Lamar and Drake, which triggered damning diss tracks and now a lawsuit. Who will reign supreme in this hip-hop battle for the ages?