When you listen to Poetry on Air, you will notice that we play different music each time to reflect the mood of the poems we're reading. This emphasises the close link between music and poetry - both of which can express feelings and change the mood of those listening. Shakespeare understood this very well when he wrote 'If music be the food of love, play on . . .' In today's Poetry on Air (RTHK Radio 4 at 10.05 am today, repeated at 6.30 pm tomorrow), we will read and discuss two pieces of poetry about the power of music to influence human emotions, and even to affect the natural world. The first of these is Orpheus with His Lute by John Fletcher, a popular and successful playwright who lived at the same time as Shakespeare. So, who was Orpheus? According to ancient Greek myth, he was a musician who played and sang so wonderfully that even nature responded. Orpheus played a stringed instrument - a lyre (hence 'lyric poetry'). Fletcher updated the lyre to a lute, the most popular instrument of his own time. Orpheus with his lute made trees, And the mountain-tops that freeze, Bow themselves when he did sing. To his music plants and flowers Ever spring, as sun and showers There had made a lasting spring. Everything that heard him play, Even the billows of the sea, Hung their heads, and then lay by. In sweet music is such art, Killing care and grief of heart Fall asleep, or hearing die. So trees and mountain-tops would bow down to Orpheus' music, and spring flowers would start to grow, even the sea would become calm. Fletcher links this myth with the power of music to bring peace of mind. Negative emotions, like 'killing care' (stress that can kill) or grief, are calmed or taken away by listening to 'sweet music'. Over 200 years later, Tennyson wrote on a connected theme in Song of the Lotos-Eaters. 'Sweet music' has the power to bring sleep, and everything is asleep in the enchanted landscape he describes. There is sweet music here that softer falls Than petals from blown roses on the grass, Or night-dews on still waters between walls Of shadowy granite, in a gleaming pass; Music that gentlier on the spirit lies, Than tired eyelids upon tired eyes; Music that brings sweet sleep down from the blissful skies. Here are cool mosses deep, And from the craggy ledge the poppy hangs in sleep . . . The last four lines have a hypnotic power, with their four-fold rhyme, repetition, and gradually increasing length like a slowing heartbeat. Surely poetry, as well as music, has the power to control and change our emotions. This is an edited version of the programme.