The Horn Concerto was written in 1971 and was the first of the ten concertos Gregson has composed to date. It is dedicated to the English horn player Ifor James, who died in 2004, and was originally written for brass band. However, in 2013, Gregson was asked by Paul Klein, Principal Horn of the Ulster Orchestra, and BBC Northern Ireland, to undertake an orchestral version for him. Gregson decided to score the concerto for a late Haydn sized orchestra, with the addition of a percussionist to add some colour to the texture.
The concerto takes as its starting point the Mozartian model, namely a sonata form opening movement, a song-like slow movement, and a jaunty rondo finale. The opening movement opens with a strident motif built on rising fourths, announced by the soloist and answered by the orchestra. This pattern of ‘question/answer’ continues until a climactic moment breaks the tension, and is followed by a lyrical second subject announced by the soloist over undulating rhythmic patterns on strings. The music is developed and recapitulated from these ideas, with the lyrical idea returning via solo clarinet, with horn answering in canon. The movement ends with the strident fourths, this time in inversion.
The slow movement is in tertiary form and opens with an expansive melody from the soloist over a repetitive harmonic and melodic pattern. This is expanded and developed, building all the while in intensity until it is interrupted by cadenza-like passages on the horn and muted brass. After a brief climax the music subsides into a moment of emotional serenity before the opening melody returns, this time on solo oboe with the horn interweaving its own answering melodic lines.
The rondo finale is more light-hearted in mood with a catchy 6/8 tune at its heart. It is twice interrupted, first by an idea built on long held chromatic notes from the soloist against a highly rhythmic backdrop (wind, brass, and snare drum), then by a slower, more thoughtful melodic idea. However, the rondo tune eventually returns and the work ends in a mood of joyous celebration.