Who wrote the theme tune to the "Picture Box"school tv programme of the 70s?

Answer 1

Tony Hatch?

Answer 2

I remember it vaguely with a spinning glass/gold box in the titles, something harpsicordy perhaps or am I thinking of the music that came with the countdown clock that always preceded it. What I do remember clearly thinking/knowing at the time was that it was by a British composer, perhaps Mendelson or Handel but can't narrow it down further.