Neil mentioned impromptu settings for the Divine Liturgy. Here's an example.
What I like most is that it was offered at a Roman Catholic Church named St. Francis Xavier. As most of you know St. Francis Xavier was one of the two or three most effective missionaries in Church history. He still is vilified by some Orthodox in Iraq and his missionary work is used by some as the reason why the Assyrian Orthodox will not merge with the Chaldean Catholics. I thank God, therefore, that this was done in none other than the St. Francis Xavier Church.