www.bbc.co.uk Celebrations marking the 250th birthday of composer Wolfgang Amadeus Mozart are being held around the world.

Many of the events are centred on his birthplace in Salzburg, and Vienna, where he made his home and died at the age of 35.

New productions of Idomeneo and The Magic Flute will be performed at opera houses in Vienna.

A giant birthday cake measuring more than two metres high will be unveiled during a street party in Salzburg.

The opening chords of the celebrations were heard in Sydney, where the city's symphony orchestra performed Eine Kleine Nachtmusik and his Divertimento No. 11 in D major from an "aquashell" floating in the harbour.

Libby Christie, managing director of the orchestra, said she was "delighted" to be kicking off the celebrations.

In the US many classical radio stations were sweeping away their usual playlists in favour of playing back-to-back Mozart.

Even in country music-obsessed Nashville there will be a concert of his Piano Concerto No 21.

Both Austrian cities will be offering visitors tours highlighting places the composer visited, including his favourite restaurants and the homes of his friends and enemies.

In Vienna a new museum has opened in the building where Mozart lived from 1784 to 1787 and where he composed The Impresario and The Marriage of Figaro.

Salzburg will also see the Vienna Philharmonic perform Mozart's Piano Concert No 18, before renowned Italian conductor Riccardo Muti leads a musical tribute.

Muti told Austrian radio that Mozart remained "very current", adding that he "knew how to say the indescribable with the simplest of means".

Surrounding the Salzburg events are dozens of shops and stalls selling all kinds of Mozart memorabilia including cuddly toys, T-shirts, baseball caps and even golf balls.

Gabi Burgstaller, Salzburg's regional leader, summed up the composer's importance, telling concert-goers: "Mozart would have existed without Salzburg, but Salzburg, this Salzburg, would not exist without Mozart."

Dedicated recitals were also due to be staged in Moscow, Prague, London, Tokyo, Havana and New York among many other cities.

Mozart, who has long been hailed a genius, was a child prodigy having composed his first symphony before the age of 10 and his first successful opera by the age of 12.

Before his early death he had created hundreds of solo and orchestral pieces, inspiring the likes of Beethoven and Wagner.