VIDEO: New York Polyphony Perform Byrd and a modern lullaby

Making recordings of quiet, spiritual music from the 16th century isn't so easy in 21st-century New York. So to record its last album, "Endbeginning," the all-male vocal ensemble New York Polyphony traveled to a medieval church in rural Lanna, Sweden. There the noise floor – the technical term for background noise – was exactly zero. In New York City, it's around 40 decibels.