George Gershwin was the first composer who genuinely straddled the worlds of "classical" and "jazz". To him music was music, and he gave as much attention to his songs and shows as he did to his more formal concert works. One reason is that he was a natural, instinctive musician rather than a trained one. He came to music in his teens: at the age of 11 he was the troublesome kid of an immigrant Jewish family with an aptitude for getting into scrapes on the streets of New York. Then his parents bought a piano, supposedly for his more studious older brother. George was fascinated, elbowed his brother aside, and started to play tunes he heard around the town. In a mere four years he became a brilliant player, left school, and got a job playing piano for a New York music publisher.

After writing songs and shows, George's big break came with "Rhapsody in Blue". This was premiered in 1924 when George was 26, and was the highlight of a worthy but rather dull experimental "Classical Jazz" concert given by the Paul Whiteman band. In the audience was Walter Damrosch, conductor of the New York Symphony Orchestra. Damrosch was sufficiently impressed to persuade the orchestra management to commission a "proper" concerto from Gershwin.

That George accepted the commission was very brave. Rhapsody in Blue, though written by Gershwin, had been entirely orchestrated by Whiteman's arranger, Ferde Grofe. For the concerto, Gershwin was going to have to do all the orchestration himself. He wrote the music of the concerto in the summer of 1925, and orchestrated it in the autumn. He then had the sense to hire an orchestra for a private run-through, so he could check out his orchestration - but made surprisingly few alterations in the light of this. Originally he planned to call the work New York Concerto, but replaced it with the factual title Concerto in F, and as such it was first performed in New York's prestigious Carnegie Hall on 3rd December 1925.

Where Rhapsody in Blue was very loosely structured, the concerto is much tighter, and the melodic ideas come thick and fast. The orchestral introduction presents three different ideas in less than 30 seconds: a percussion motif on timpani, four bars of Charleston rhythm, and a skipping tune on the bassoon. After the orchestra has played with these for a little, the solo piano enters with the real main tune of the movement (indeed of the whole concerto). This is worked up to a climax by the orchestra, then the Charleston takes over and gradually subsides to a beautiful slower melody on strings and cor anglais. This is given more fully, then the Charleston is coupled with a speeded up version of the slow melody. Gradually the various ideas come together, including the opening timpani motif, leading to a huge restatement of the first tune. From here to the close is a riot of tunes all of which fit together like a jubilant jigsaw.

The slow movement starts as a blues number, with a prominent trumpet melody, but the piano soon pushes it along more briskly. A violin solo slows it down again, and the piano muses dreamily, until the orchestra ushers in a big romantic Hollywood-style melody. The piano plays with it, accompanied by a cello quartet, and then works up to a passionate climax - after which the movement fades peacefully.

The finale is another riot of fun, and ties the whole concerto together by incorporating both the main tune from the first movement and the Hollywood tune from the slow movement - see if you can spot them. Indeed the big climax towards the end is not the theme of the finale at all, but the main theme from the first movement. Even the timpani motif from the very beginning of the concerto reappears on the last page, emphasising the originality and unity of this landmark in 20th century American music.