Radio 3 - Interlude at 1am

[Sweet G]

There is a lovely little snippet of music about 30 secs long in between "Composer of the Week" and "Through the Night" and is always played at 1am. Its a woodwind instrumental piece (clarinet?) and makes me think of a swallow swooping and rising over a corn filed as the sun sets on a summer's evening. I absolutely adore it and always wondered if it was part of a longer piece of music and if so which one.

Thanks