Douglas Tate died on the 16th November 2005.
You can read about him here:
http://harmonica.co.uk/SPAHTateTributeAug06.pdf
You may listen to his music here:
https://douglastate.bandcamp.com/album/an-evening-with-tate-and-collis
and spend an evening with him here:
https://douglastate.bandcamp.com/album/an-evening-with-tate-and-jenkyns
To mark theĀ beginning of the 15th year since he died you may now download his book of Advanced Exercises and Studies for the Chromatic Harmonica here at no cost: