Hymn meter
Hymn meter, in Western liturgy and literature, is the general metrical scheme in which hymns are recited or sung. Three metrical schemes are generally recognized, all (usually) in four-line stanzas rhyming a-b-c-b (or a-b-a-b). English minister and hymn writer Isaac Watts, who wrote hundreds of hymns and was instrumental in the widespread use of hymns in public worship in England, is credited with popularizing and formalizing these meters, which were based on English folk poems, particularly ballads. Common metre. Common metre has alternating lines of iambic tetrameter and iambic trimeter organized  in four-line stanzas. This is also called ballad meter, since many English ballads employ this structure. Examples. "Amazing Grace": Long metre. In long metre, stanzas consist of lines of iambic tetrameter. Examples. "When I Survey the Wondrous Cross": Short metre. Short meter has two lines of iambic trimeter, a line of iambic tetrameter, and a final line of iambic trimeter.