The Harp and Bowl style of worship, which features musical prayer, derives its name from Revelation 5:8, which describes heavenly creatures which each "had a harp" and "were holding golden bowls full of incense, which are the prayers of the saints."
As used by the International House of Prayer, this style was first developed by Noel Alexander and Larry Bridge in late 1990 at Metro Vineyard Fellowship's Lee's Summit location. It involved people praying while the worship team continued playing, interspersed with others who sang their prayers or sang portions of the prayers being prayed. Noel coined the expression "harp and bowl" from Revelation 5:8, and an assistant pastor, Greg Mira, used Noel's comments as the basis for a sermon he later preached at Metro Vineyard Fellowship's Grandview location. In 1991, Greg Mira also published a book with the same title.
While this expression ceased in the prayer rooms of Metro Vineyard Fellowship/Metro Christian Fellowship after a few years, the concept remained. When the International House of Prayer was begun in 1999 by Mike Bickle of Metro Christian Fellowship and others from that church, they sought to develop a style of worship and intercession similar to the earlier "harp and bowl" prayer meetings.
A common feature of harp and bowl worship is antiphonal singers, who use the Bible as a song book along with spontaneous instrumental accompaniment.
This style can sustain long periods of worship - for instance, the International House of Prayer in Kansas City has used this method of worship to sustain a prayer meeting since September 1999.