Well my (paternal) grandfather used to play the melodeon while standing on his head, but that wasn't English Folk, that was Music Hall. He was (3rd generation) Irish anyway.

If my maternal granny's side is anything to go by, the main instrument was the Parlour Piano, all walnut and ivory, with brass candlesticks. Nobody ever played it, because the parlour was damp, the piano was rusty inside, and it had never been tuned in fifty years. We demolished it one bonfire night, and it was so rotten we couldn't get it to burn until someone doused it in paraffin. They sang a lot though- usually unaccompanied, old traditional English songs like Show Me The way To Go Home, Come Back to Sorrento, The Happy Wanderer, Ave Maria, The Laughing Policeman, The Hole In The Elephant's Bottom (My dad's party piece when several bottles down), Cardigan The Fearless, Eileen Og, Hullabalooballay, Down Came The Blind, Donald Where's Your Troosers, Mother Machree, and so on. I think it was meant to be in harmony, but not really sure.