Getting music out there - 1780s style
You could say that Wolfgang Amadeus Mozart was the man who invented the piano concerto. The product of a marriage made in heaven, this most popular of musical forms - putting the soloist out in front with an orchestra in full support - stemmed from the development of the instrument alongside a genius to compose for it.
The harpsichord was the keyboard played by Bach. By Mozart's time - he was born in 1756 - it had been superseded by the fortepiano, a prototype for what would become our concert grand.
The fortepiano's hammer action offered more scope than the plucked strings of the harpsichord, not least its ability to vary its tone. The clue is in the name - forte is Italian for loud, piano means soft.
Still, it didn't have the power we associate with the seven-foot king of today's concert stage. Mozart scored for a much smaller band than the full-blown symphony orchestra that accompanies, say, Tchaikovsky or Rachmaninoff.
Mozart had been trying his hand at composition from a very early age, arranging others' work for the keyboard. These pieces are catalogued as the first four of his 27 concertos.
It was his move from provincial Salzburg to the imperial capital of Vienna that brought a firmer focus on to the possibilities of the form, not least because he had a living to make.
Writing was one source of income, but it wasn't enough. There was no such thing as royalties back then. You got a flat fee when your music came out in print. From then on, it was the publisher who profited from it.
Mozart was a brilliant pianist, and this was how he made his music pay. He wrote his concertos to showcase his own talent. The more he wrote, the more the money rolled in.
His father, Leopold - a musician and composer himself who'd come from Salzburg to visit - was astonished at the pace his son set for himself. As well as writing prolifically, he was out performing virtually every night.
The day the elder Mozart arrived, the finishing touches were being put to a concerto that would have its première that very evening.
Removal men were a constant presence, transporting the piano from the house on Schulerstrasse behind the cathedral (now the Mozart Museum, with its entrance where the back door used to be, on Domgasse) to wherever the concert was on.
The piece that Leopold heard the night he arrived was the Piano Concerto No 20 in D minor. No 21 followed just four weeks later.
Mozart was the soloist, in one of his regular venues, the Mehlgrube (the Flour Pit) on the new market square on the site of what is now the five-star Ambassador Hotel.
A measure of the success he was having was that Leopold was able to report that this particular concert brought in 559 guilders - about €5,000 in today's money.
The C major Concerto No 21 has become one of the most enduringly popular of all Mozart's creations. Its slow movement became a huge hit 50 years ago, as the soundtrack to the tragic love tale of a Danish tightrope dancer and a Swedish army officer.
The movie may be long forgotten, but its title, the name of its heroine, lives on. The Piano Concerto No 21 is now known as the Elvira Madigan. Mozart first performed it on this date, March 10, in 1785.
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