And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints. —Revelation 5:8

The book of Revelation is symbolic in nature and paints a beautiful picture of the saints gathered around the throne with harps in their hands, singing the song of redemption. These harps in heaven are not literal but symbolic of the praise being given to God. They typify the unity and oneness that come from being in harmony with the Spirit.