O the depth is a devotional work, suitable as an introit or short anthem, which couples together a passage from the New Testament (Romans 11) and a single verse from the Old Testament (Isaiah 55) which McGlade felt complemented each other very well. The beautiful texts, both of which dwell upon God’s unfathomable wisdom and knowledge, naturally lend themselves to expressive treatment. In this setting, with its long legato lines, gentle dissonances and feeling of space and poise, the composer conveys something of the sense of wonder and majesty contained in the words.