Grammy Award-Winning songwriter Amy Wadge fell in love with the harmonica after winning one in a fancy dress competition (she was dressed in a bin liner!). Now she investigates the history and potential of the diatonic instrument, a European the toy which in the hands of expert players became the iconic sound of the Mississippi Delta and the Chicago Blues. Not bad for what was originally a child's toy produced then, as now, in Germany!

As music historian Christoph Wagner explains, the very first example of the instrument goes back to Vienna. But millions would soon find their way to the USA, taken there by German emigres fleeing poverty. The poor person's introduction to music, the harmonica would soon find its way to around the globe, from Britain to Australia and even China. But it was in America that it scored its biggest success. And it was there that harmonica technique underwent a transformation, as Chicago -based Joe Filisko explains. Instead of exhaling air, blues players would draw air in, and bend notes to achieve the characteristic sounds of the blues.

Amy tries her hand at bending, under the expert tutelage of Steve Lockwood - one of very few people to have studied the harmonica to degree level, and she speaks to one of Britain's best-known players, Paul Jones.

It may be the sound of the amplified harmonica popularised the instrument in the 1950s and 1960s, but has it moved on from Chicago Blues and Beatles covers? Canadian beat-boxer Benjamin Darvill - "Son of Dave" - has explored new possibilities with the instrument, and with an original sound that's been heard in edgy TV dramas and commercials. Just going to prove that for all its limitations - 10 holes and 3 octaves - there's life yet the harmonica.