In 1874, Monk became a singing teacher at King’s College. In 1876, he became a teacher at the National Training School for Music. In 1878, he started teaching at Bedford College. In addition, he was music director for almost four decades at St. Matthias, Stoke Newington, London, and was the first musical editor for Hymns Ancient and Modern, the historic hymnal which sold 60 million copies.

Author Thomas Hardy wrote of Monk’s editing for Hymns Ancient and Modern:

Stripped of some of your vesture
By Monk or another. Now you wore no frill,
And at first you startled me. But I know you still,
Though I missed the minim’s waver
And the dotted quaver.