The Ocean Drum, pictured right, is much more than the sum of its parts - it is a fascinating trip to an isolated seashore, with only the cry of the gulls missing. The playing head is beautifully illustrated with fish motifs. The other head is transparent plastic, revealing that the drum contains lots of tiny metal balls. As you move the drum, the balls rush across the taut plastic, creating the sound of the sea.

The authenticity of sound is astonishing - move the drum carefully and you have everything from the sudden crash of surf to the “melancholy, long, withdrawing roar” of Matthew Arnold’s Dover Beach.

The other surprise is its sheer volume. You can coax a sound loud enough to deceive a listener into thinking that there is some kind of electronic amplification at work, which, triumphantly, there is not.

Apart from its obvious place in creative music, teachers will find all manner of classroom uses for this instrument - perhaps, for example, as a calming device at circle time. It comes in two sizes. A soft beater is provided so that the instrument can also be played conventionally.