The quality of being pleasing to the ear is known as euphony. The term derives from late Middle English: from French euphonie, via late Latin from Greek euphōnia, from euphōnos ‘well sounding’ (based on phōnē ‘sound’). When something is pleasant to hear, it is euphonic, in that we enjoy listening to it.

Christmas songs are an excellent example of euphony at work, and what makes them euphonic is their use of repetition, rhyme and rhythm, and a variety of festive sound effects in their lyrics. The fact that we hear them on repeat—throughout the season and every year—also gives Christmas songs a comforting familiarity.

‘Jingle Bells’

Written by James Lord Pierpont (1822–1893) and published under the title ‘The One Horse Open Sleigh" in 1857, and now one of the best-known and commonly sung Christmas songs in the world, ‘Jingle Bells’ shows these various euphonic features at work:

Jingle bells, jingle bells,
Jingle all the way.
Oh what fun it is to ride
In a one-horse open sleigh, hey!

The word ‘jingle’, with its hard and soft ‘g’ sounds, sounds like what horse bells do; together with ‘bells’ the phrase has a dactylic triple beat ending in a sibilant sound. Another triadic form in the close repetition of ‘jingle’ three times gives the lines a plosive, skipping quality, emphasised by the ‘jing’. The words ‘Oh’ and ‘hey’ convey shouts of delight; the word ‘sleigh’ is sibilant and airy, like a sledge slicing through crispy snow.

‘White Christmas’

Famously first sung by Bing Crosby, and written by Irving Berlin for the musical film Holiday Inn (1942), ‘White Christmas’ is the world’s best-selling single in physical form, having sold more than 50 million copies:

I'm dreaming of a white Christmas
Just like the ones I used to know
Where the tree-tops glisten and children listen
To hear sleigh bells in the snow

The long ‘i’ sounds in ‘I’m’ and ‘white’, recalling Crosby’s crooning delivery, draw out and slow down the delivery of the famous first line. The ‘m’ sounds carried from ‘I’m’ to ‘dreaming’ give the line soothing hum. The word ‘Christmas’, with its euphonic sibilance, is naturally wistful, as are the words ‘glisten’ and ‘listen’, which have a soft, skating quality. The phrase ‘tree-tops’ is light and tripping, while ‘sleigh bells in the snow’ ends the verse with a sweep of ‘s’ sounds, sounding like what sleds do in sliding over a fresh snowfall.

Above all, it’s the timeless replaying of these songs, and repeating of the phrases ‘Jingle Bells’ and ‘White Christmas’, that make them so pleasing and memorable, and dear to people’s hearts:

Sound gifts that keep on giving,
Year after year,
Giving lessons of what listeners
Most love to hear.