Carols were first sung in Europe thousands of years ago, but these were not Christmas Carols. They were pagan songs, sung at the Winter Solstice celebration as people danced round stone circles. The Winter Solstice is the shortest day of the year, usually around the 22nd December. The word Carols actually means dance or a song of praise and joy! Carols used to be written and sung during all four seasons, but only the tradition of singing them at Christmas survived!
Early Christians took over the Pagan Solstice celebrations for Christmas and gave people Christian songs to sing instead of pagan ones. In AD 129, a Roman Bishop said that a song called ‘Angel’s Hymn’ should be sung at a Christmas service in Rome. Another famous early Christmas Hymn was written in 760 AD by Comas of Jerusalem for the Greek Orthodox Church. Soon after this many composers all over Europe started to write carols but not many people liked them, as they were all written and sung in Latin, a language that the normal people couldn’t understand. By the time of the Middles Ages (the 1200s), most people had lost interest in celebrating Christmas altogether.
This was changed by St. Francis of Assisi, when in 1223 he started his Nativity Plays in Italy. The people in the plays sang songs or ‘canticles’ telling the story during plays. Sometimes the choruses of these new carols were in Latin, but normally they were all in a language that the people watching the play could understand and join in! The new carols spread to France, Spain, Germany and other European countries.
The earliest of carols like this was written in 1410, but sadly only a very small fragment of it still exists. It was about Mary and Jesus meeting different people in Bethlehem. Most Carols from this time and the Elizabethan period are untrue stories, very loosely based on the Christmas story, about the holy family and were seen as entertaining rather than religious songs. They were usually sung in homes rather than in churches! Traveling singers or Minstrels started singing these carols and the words were changed for the local people wherever they were traveling. One carols that has changed like this is ‘I Saw Three Ships’.
When, in 1647, Oliver Cromwell and the Puritans came to power in England, celebrating Christmas and singing carols was stopped. However, the carols survived as people still sang them in secret. Carols remained mainly unsung until Victorian times when two men; Sandys and Gilbert published old Christmas music collected from villages in England.
Before carol singing in public became popular, there were sometimes official carol singers called ‘Waits’. These were bands of people led by important local leaders (such as council leaders) who had the only power in the towns and villages to take money from the public (if others did this, they were sometimes charged as beggars!). They were called ‘Waits’ because they only sang on Christmas Eve (this was sometimes known as ‘watchnight’ or ‘waitnight’ because the shepherds were watching their sheep when the angels appeared to them) when the Christmas celebrations began.
Charles W. Jones  relates that in England the Puritans could not end customs of Christmas, however stringently legislated against.
The restoration of the monarchy (1660) restored Anglicanism, and the Puritan clergy were expelled from the Church of England under the terms of the Act of Uniformity (1662).
Even though Christmas was again observed in England after the Restoration in 1660, carols continued an underground existence for generations primarily in rural England. Almost no new “carols” were published in England during the following 150 years. However, a tradition that strong could not be entirely suppressed. Some carols that were composed included: The Wassail Song, The Twelve Days of Christmas, The Holly and the Ivy, Adeste fideles (O Come, All Ye Faithful) – from France, Les anges dans nos campagnes (Angels We Have Heard on High) – from France. And although Christmas was once again observed in England, the same was not true in Scotland, where the conservatives held sway for nearly three centuries. Christmas was not a public holiday in Scotland until 1958.
The hymns of early American settlers were metrical psalms. The Pilgrims preferred Ainsworth’s Psalter, printed in Amsterdam in 1612. The Massachusetts Bay Colony also used Ainsworth’s, but generally preferred Day’s Sternhold and Hopkins, and possibly the psalters of Este (1592) and Ravenscroft (1621). These and several other popular collections of that day served until publication of the Bay Psalm Book (1640), which remained a popular volume for well over a century. It contained no music until its ninth edition, and then it had only 13 tunes to accommodate the entire contents.
The Virginia settlers likely had the book of Sternhold and Hopkins published by John Day in 1561 and 1562, with possibly Este’s whole Book of Psalms from 1592 or Alison’s Psalter, 1599.
The American public was largely untutored in music, and the practice of “lining out,” already known in England, became an important tutorial device. A deacon sang each line, and the congregation repeated it. The practice declined as people learned to use the instructions printed in most books.
Charles W. Jones, Saint Nicholas of Myra, Bari, and Manhattan (Chicago: University of Chicago, 1978, p. 317 of 1988 paperback edition.)
 The full title was The Whole Book of Psalms faithfully translated into English Metre, whereunto is prefixed a discourse declaring not only the lawfullness, but also the necessity of the heavenly Ordinance of singing Scripture Psalms in the Churches of God. One of the compilers of the Bay Psalm Book was Rev. Richard Mather (1596-1669), who was the father of Rev. Increase Mather (1639-1723) and the grandfather of Rev. Cotton Mather (1663-1728). The last edition of the Bay Psalm Book was published in America in 1773, 113 years after its initial publication. The last publication in England was in 1754; the last in Scotland was in 1759.