Long Metre or Long Measure, abbreviated L.M. or LM, is a poetic metre consisting of four line stanzas, or quatrains, in iambic tetrameter with alternate rhyme pattern a-b-a-b. The term is also used in the closely related area of hymn metres. When the poem is used as a sung hymn, the metre of the text is denoted by the syllable count of each line; for long metre, the count is denoted by 126.96.36.199, 88.88, or 88 88, depending on style. It is similar to common metre (for poems or melodies denoted as 188.8.131.52, 86.86, or 86 86) which consists of four lines in alternating iambic tetrameter and iambic trimeter.
Poets and composers have used long metre for more than a millennium: Venantius Fortunatus (c.530-c.600/609) wrote Vexilla regis, and probably also wrote Quem terra, pontus, aethera, both of which are in long metre. The same metre is also found in more recent melodies and arrangements: Psalm 100, All People That on Earth Do Dwell, is sometimes sung to an arrangement of the calypso tune used in Jamaica Farewell, and the song Hernando's Hideaway from The Pajama Game is also largely in long metre; Jimmy Crack Corn is in long metre, with frequent metric variations, but the refrain is in 88 86.