For another 5 days, a 60-minute BBC4 program on Tallis, Byrd and the Tudors is available to everyone (in the UK at least) via the BBC iPlayer streamer.
To quote the blurb: "Simon Russell Beale explores Western sacred music. He looks at the works of Thomas Tallis (pictured) and William Byrd, part of the Renaissance in Tudor England."
The program includes some stunning shots of London.
(Available for 5 more days - 30 days if you download the 600mb file)