Mercy, Mercy

The original key for the song "Mercy, Mercy" by Hillsong United is D. The song was first released on the album "Zion" in 2013. It is an uplifting worship song that reflects on God's mercy and grace. The track was written and composed by Joel Houston, Matt Crocker, and Ben Tennikoff. One interesting fact about the song is that it features a mix of electronic and rock elements in its musical arrangement. The melody is characterized by catchy guitar riffs and strong vocals, creating a powerful and engaging sound.