"The singing of our sacred hymns, written by the servants of God, has a powerful effect in converting people to the principles of the gospel and in promoting peace and spiritual growth."

- Heber J. Grant, Teachings of Presidents of the Church: Heber J. Grant, (2011), 164–71, Chapter 18: The Song of the Heart
http://www.lds.org/manual/teachings-heber-j-grant/chapter-18?lang=eng

"Some of the greatest sermons are preached by the singing of hymns. Hymns move us to repentance and good works, build testimony and faith, comfort the weary, console the mourning, and inspire us to endure to the end. ...

"Music has boundless powers for moving families toward greater spirituality and devotion to the gospel. Latter-day Saints should fill their homes with the sound of worthy music."

- First Presidency Preface to Hymns
http://www.lds.org/music/guidelines/first-presidency-preface-to-the-hymns?lang=eng