THE rain, which had held off for most of the day, finally started just as the orchestra was tuning up.

For a minute, it looked as though this evening of John Williams film music might end with us all getting wetter than the cast of Jaws.

Fortunately, the weather had nothing worse in store than some light showers and chilly winds, and it takes more than that to spoil a night of John Williams.

The first night of Bournemouth Symphony Orchestra’s Investec Proms in the Park season was devoted to the most successful composer ever to work in films.

Still writing at the age of 85, he’s scored 102 movies, won five Oscars and received more nominations than you can wave a baton at.

In the first half, with the sky still light and the audience’s powers of concentration undimmed by Pimms, the orchestra slipped some of Williams’ quieter music into the programme.

Even in a wide open park, it was possible to be riveted by the orchestra’s delicate performance of pieces from Angela’s Ashes, Memoirs of a Geisha and the main theme from Schindler’s List.

There was some blockbuster material in there too, though, including a first chance to hear the BSO perform three fine selections from Williams’ 2015 score to Star Wars: The Force Awakens.

After the interval, the show was almost entirely devoted to music from the kind of movies that break box office records.

Opening the second half was the theme from Superman – a piece that’s about as exciting as film music gets, with the BSO at full throttle. There was Jaws, Star Wars: Attack of the Clones, and a piece from one of Williams’ most gorgeous scores, Hook.

But the climax of the show was something even more special. The John Williams Celebration Suite was the BSO’s own amalgam of four of the maestro’s most famous pieces. (They sought, and received, permission from the man himself to stitch the music together.)

Hedwig’s Theme from Harry Potter gave way to Jurassic Park, then to the Flying theme from E.T. and finally the Throne Room and End Title from the original Star Wars.

This 20-minute sequence will stay in the memory for a long time. The four pieces, from different phases of a long and distinguished career, were performed with dazzling energy by the BSO under conductor Victor Aviat, alongside a spectacular and perfectly timed display of pyrotechnics. There are very few composers whose music merits accompaniment by fireworks, but John Williams is one of them.

Many in the audience had guessed what the encore would be. Sure enough, Raiders of the Lost Ark, with more fireworks, sent the audience home smiling, with any thoughts about the weather long banished.