This one comes from an appearance on the Tom Jones variety show. Though the description suggests that this is a trio, it's not. It's a lovely performance that Harry gives of "Try to Remember," and towards the end Tom Jones (a fellow Welshman with Secombe) and Florence Henderson come in to basically sing back-up. It may not have been intended to be back-up, but with his booming voice it's hard to be. I do suspect it was, though, since Tom Jones to his credit does a nice job singing harmony.