Johnny

A lagerphone is basically a big stick (broom handle, etc), with beer-bottle tops fixed to it fairly loosely so they rattle like very faint bells. You play it by banging it on the floor and/or drawing a shorter stick (half of a washing tongs, etc) across the bottle tops - this adds a kinda washboardy sound. Very useful if you've got a non-musician you want to let join you.

Wassail! V