He was a choirmaster, writer about singing and author and editor of hymns and carols. Helmore's father was a congregationalist minister (also called Thomas). During the boy's childhood the family moved from Kidderminster to Stratford-upon-Avon, where Helmore later trained his father's choir and taught in a school which his father had founded. In 1837, he began his studies at Magdalen College, Oxford, graduating in 1840. He was or­dained in the Church of England in the same year, and took up a curacy at St Michael's, Lichfield, where he was also a priest-vicar in the Cathedral. Two years later he was appointed as precentor and vice-prin­ci­pal at St. Mark's College, Chelsea, where the principal was Derwent Coleridge (son of the poet Samuel Taylor Coleridge). He soon came to be on friendly terms with his new colleague, and in 1844 he married Kate Pridham, who was Derwent Coleridge's sister-in-law. His main duty at St. Mark's was to train the students to sing a daily unaccompanied choral service in the college chapel. In the basic musical training he was assisted by John Pyke Hullah. The choir's repertoire grew to include such as the anthems of Gibbons and Byrd and the motets of Palestrina, Vittoria and Marenzio. Helmore's growing reputation as a choirmaster led to his appointment in 1846 as mas­ter of the chor­is­ters in the Chapel Royal, St. James's, where one of his early pupils was Arthur Sullivan. He continued as precentor at St. Mark's, however, until 1877. He was appointed as executor of the will of Chauncy Hare Townshend, and on the latter's death in 1868 together with co-executrix Angela Burdett-Coutts, 1st Baroness Burdett-Coutts, he undertook the responsibility of founding an elementary school in London, which was finally opened in Rochester Street, Westminster, in 1876. His interest in plainsong led him to make several visits, in and after 1875, to the Abbey of Saint Gall in Switzerland, to examine an ancient manuscript supposed to be an accurate copy of a book on Gregorian chant written by Saint Gregory himself.

He was a choirmaster, writer about singing and author and editor of hymns and carols. Helmore's father was a congregationalist minister (also called Thomas). During the boy's childhood the family moved from Kidderminster to Stratford-upon-Avon, where Helmore later trained his father's choir and taught in a school which his father had founded. In 1837, he began his studies at Magdalen College, Oxford, graduating in 1840. He was or­dained in the Church of England in the same year, and took up a curacy at St Michael's, Lichfield, where he was also a priest-vicar in the Cathedral. Two years later he was appointed as precentor and vice-prin­ci­pal at St. Mark's College, Chelsea, where the principal was Derwent Coleridge (son of the poet Samuel Taylor Coleridge). He soon came to be on friendly terms with his new colleague, and in 1844 he married Kate Pridham, who was Derwent Coleridge's sister-in-law. His main duty at St. Mark's was to train the students to sing a daily unaccompanied choral service in the college chapel. In the basic musical training he was assisted by John Pyke Hullah. The choir's repertoire grew to include such as the anthems of Gibbons and Byrd and the motets of Palestrina, Vittoria and Marenzio. Helmore's growing reputation as a choirmaster led to his appointment in 1846 as mas­ter of the chor­is­ters in the Chapel Royal, St. James's, where one of his early pupils was Arthur Sullivan. He continued as precentor at St. Mark's, however, until 1877. He was appointed as executor of the will of Chauncy Hare Townshend, and on the latter's death in 1868 together with co-executrix Angela Burdett-Coutts, 1st Baroness Burdett-Coutts, he undertook the responsibility of founding an elementary school in London, which was finally opened in Rochester Street, Westminster, in 1876. His interest in plainsong led him to make several visits, in and after 1875, to the Abbey of Saint Gall in Switzerland, to examine an ancient manuscript supposed to be an accurate copy of a book on Gregorian chant written by Saint Gregory himself.