Determining which song was Elvis' biggest hit is a tricky thing, as he has enjoyed one of the longest and most successful runs in chart history.

However, musicians have been reserving space for King for decades. Find three songs that sample King and his speeches, below.

Monday was Martin Luther King Jr. Day, with the civil rights leader’s birthday actually being Jan. 15. A group celebrated Dr.

In "Why?" Simone channels the collective grief of the civil rights movement, while also challenging her audience to continue the fight for equality.

Determining which song was Elvis’ biggest hit is a tricky ... Decade-by-decade milestones in the life — and afterlife — of the King Happy 90th birthday, Elvis! Fans from around the world ...