Unaccompanied singing is surely the oldest form of music on Earth. I imagine the earliest tunes being lullabys gently whispered into a baby's ear. This field recording from 1951 has an unearthly, magical quality as two unidentified Burundian girls sing Akazélé – a sweet, strange lullaby in perfect but spooky concord. It feels simultaneously as old as the Earth and as fresh as the future.
By way of contrast, the tight, bright and punchy American harmony gospel act Take 6 came to my attention on the soundtrack to Do the Right Thing. They have an extraordinarily controlled vocal quality that simply leaves no room for instruments. Here they arrange Handel's O Thou That Tellest Good Tidings to Zion, from the Messiah, in a gospel style – complete with guest vocalist Stevie Wonder. Sacrilege.
Choral music came to the fore this week, with representation from all over the globe. And as the depth of the contributions showed, it could certainly handle a week to itself. The Morriston Orpheus male voice choir are one of Wales's finest vocal ensembles, and here they sing the emotional and popular song Myfanwy, written by Joseph Parry and first published in 1875. Not a dry eye in the house.
Such is my yen for harmony that I've chosen just one special solo voice. Musical archaeologist John Lomax, father of Alan Lomax, recorded Vera Hall in 1937 for the Anthology of American Folk Music. He wrote afterwards that she had the loveliest voice he had ever recorded. Trouble So Hard was remixed by Moby in 2000 as Natural Blues.
Four brothers started the jazz vocal group the Mills Brothers in the 1920s, singing in front of their father's barbershop in Piqua, Ohio. When a kazoo was lost, the sound was imitated vocally – and so one of the most extraordinary groups in musical history was born. Purists may deride the rhythm acoustic guitar in the background, but it would take a heart of stone not to swoon over their rendition of Caravan.
In the US, there is an a cappella industry based on college groups. A televised national competition means the form has never been more popular. The inspirational Swingle Singers' version of Grace Jones' Libertango gets the easy-listening nod.
A cappella singing has always been integral to folk music, and expert readers offered many outstanding nominations – from Steeleye Span to Sandy Denny, Oysterband to Port Isaac's Fisherman's Friends. In the end, though, Hunting the Hare – a non-Guardian pursuit, admittedly – was irresistible to my ears, the meltingly sweet two-part harmonies of Kate Rusby and Kathryn Roberts making bloodsports seem almost fun.
Not typical of their output, Knots by Gentle Giant presents a musical homage to RD Laing's philosophical conundrums and wordgames from Octopus, their impossibly complex and bloody-mindedly original fourth album. The band used to play this madrigal vocal workout live – to the delight of their fans, myself included.
When Paul McCartney sang "Georgia's always on my mind, " he was alluding to both Hoagy Carmichael's classic and the Caucasian state back in the USSR. Georgian choral singing is little known in the UK, but Kate Bush lifted a whole section of Tsintskaro for her song Hello Earth. I've chosen a version by the Rustavi Choir. This is stunning, haunting, beautiful music.
"The voice is an instrument in itself, " says Marie Daulne of Congolese-Belgian a cappella quintet Zap Mama. Mixing pygmy chants, beatboxing and Zairean pop, the world fusion sound of Brrlak! is exciting, infectious and original.
Only Remembered is a very powerful and moving hymn, written by John Tams in its current form. Often sung as a requiem for the dead of world war one – it features in the play War Horse – it has been taken up in certain quarters as a rallying cry to change the world for the better. This rendition by Coope Boyes and Simpson reduces me to tears every time I hear it.
Ladysmith Black Mambazo are a Zulu choir formed in 1960 by Joseph Shabalala, who found their distinctive sound in a series of dreams. The results were so good that they were forbidden to enter vocal competitions lest they should sweep the board. Their first album was finally released in 1973; it featured Nomathemba (Mother of Hope), their signature anthem and first hit single.
Picking this playlist was the most wonderful way to spend the holidays; of the 350-odd pieces of music recommended, I liked about 320. This number had to be reduced to 13. So to end, something remarkable: sit back, close your eyes and enjoy Thomas Tallis's little piece of vocal heaven Spem in Alium (Hope in Any Other). The 40-part Renaissance motet is a phenomenal example of unaccompanied singing, especially when tackled by the wonderful Tallis Scholars. Bliss!