On Martin Luther King Jr. Day 2021, Stevie Wonder took to Twitter to read an open letter he had penned to the late Civil Rights leader.

King was assassinated in 1968, and the campaign to mark his birthday, January 15th, as a national holiday began not long after. Despite widespread efforts, the holiday wasn’t signed into law until 1983 and wasn’t officially observed for the first time until 1986.

In 1981, Wonder, already a veteran creator of social justice-minded music, gave the campaign to recognize MLK Day a big boost when he released “Happy Birthday”—both an unfiltered rebuke of MLK Day opponents and an enduring celebration anthem. As Wonder sings to open the song, “You know it doesn’t make much sense / There ought to be a law against / Anyone who takes offense / At a day in your celebration.”

 Stevie Wonder – “Happy Birthday”

As the song grew in popularity, so did the MLK Day movement. Today, we honor the legacy of Dr. Martin Luther King Jr. on the third Monday of January, every January, and several generations of Americans have grown up learning his message. On paper, it sounds like a win. The fact that MLK Day exists points the ship in the right direction, but anyone who’s been paying attention knows that there is still an untold amount of work to be done in order to reach King’s storied dream for our country.

Wonder himself is the first to admit that we’ve barely scratched the surface of the centuries-old problem of racial injustice. As he notes in his open letter to Dr. King, reading the braille note aloud in a video posted to Twitter, “I met you when I was 14 years of age. You were a true hero and became an inspiration. I’ve been blessed to write songs of love, hope, and motivation—many of them inspired by your life. More than any award that I’ve ever received, I want you to know that I’m thankful how you influenced my place of love, which allowed me to try to push the needle of love and equality forward. It is painful to know that needle has not moved one iota. For 36 years, we’ve had a holiday honoring your birthday and principles, yet you would not believe the lack of progress. It makes me physically sick. … What we say has not been what we do, and this country must reconcile our words and deeds. Until we turn our mouth movement into righteous action, we’re doing our nation, God, and your memory an injustice.”

Related: 10 Things You Never Knew About Stevie Wonder

He continues by calling on the incoming President and Vice President to establish a “Truth Commission” which would codify the inequitable history of our country as incontrovertible fact and facilitate an eventual healing process. Notes Wonder, “We must define the truth and the facts that support them and declare them absolute. … I’m calling on President Biden and Vice President Harris to launch a formal government investigation to establish the truth of inequality in this country. This truth will validate the history and this commission will recommend reconciliation. Without truth, we cannot have accountability. Without accountability, we cannot have forgiveness. Without forgiveness, we cannot heal.”

Watch Stevie Wonder read his open letter to Dr. Martin Luther King Jr. or read a full transcript of the letter below:

Stevie Wonder – Open Letter to Dr. Martin Luther King Jr.

I met you when I was 14 years of age. You were a true hero and became an inspiration. I’ve been blessed to write songs of love, hope, and motivation—many of them inspired by your life. More than any award that I’ve ever received, I want you to know that I’m thankful how you influenced my place of love, which allowed me to try to push the needle of love and equality forward. It is painful to know that needle has not moved one iota. For 36 years, we’ve had a holiday honoring your birthday and principles, yet you would not believe the lack of progress. It makes me physically sick.

I am sick that politicians try to find and easy solution to a four-hundred-year problem. I am sick of some people using God for a convenience rather than a commitment. I am sick of lies and deceit that dominate our reality. I am sick that truth is struggling to be heard and defended. What we say has not been what we do, and this country must reconcile our words and deeds. Until we turn our mouth movement into righteous action, we’re doing our nation, God, and your memory an injustice. Until what we say is what we do, there is no truth. It is just repeating and rewriting history, just as we have for the last four hundred years.

We must define the truth and the facts that support them and declare them absolute. Those who promote lies and false truth must be held accountable. It is time to formally seek the truth and formally declare facts. We need a ‘Truth Commission’ that forces this country to look at its lies. I’m calling on President Biden and Vice President Harris to launch a formal government investigation to establish the truth of inequality in this country. This truth will validate the history and this commission will recommend reconciliation. Without truth, we cannot have accountability. Without accountability, we cannot have forgiveness. Without forgiveness, we cannot heal.

It is time for all to take the only stand. We cannot be afraid to confront a lie and a liar. Those in leadership who won’t or don’t acknowledge the truth should be held accountable.

Dr. King, these times require courage, as they did when you lived and paid the ultimate price. On this day, a day in your honor, I pledge to have to courage to say what I see and acknowledge what I hear. In your spirit, I call on all those in the Senate to speak truth to what they know, that they can physically see, and begin the steps of accountability, forgiveness, and then healing.

With a heavy heart and a hopeful spirit, Dr. King, I am Stevie.