A friend recently asked me to explain what a hymn is, and it is a great question. Here are a few observations. Feel free to comment and add any of your own.
1. A hymn is not determined by when it was written. The date is irrelevant. Many hymns are being written today — usually more modern in style and easier to sing.
2. Hymns often consist of a progression of lyrics, thus the need for multiple verses. (e.g., progressing from the incarnation to the consummation)
3. Hymns are generally more eloquent and theological, and for that reason, they appeal to the cognitive part of us. Hymns inspire by reminding believers of specific doctrinal truths.
4. Hymns are usually laden with complex truths, which makes them suitable to pair with praise choruses that are often simpler and more emotive. We need to worship in both spirit and truth.
5. Hymns often repeat words, especially during a refrain — a trait that they share in common with praise choruses.
6. Hymns are not inerrant. Some are well-written and worth singing, while others are not. Some wonderful hymns have been treasured by the church and passed down for centuries.
7. Hymns acquire deeper meaning over time as Christians sing them in church, at weddings, at funerals, decade after decade. As a Christian sings them over the years, the truth expressed in the lyrics becomes more precious.
8. Older hymns often have a difficult melody line to sing and can be out of the vocal range of many people. The notes and style are not sacred, however, so musicians should feel free to adjust the melody and arrangement for the sake of the congregation.