They were beautiful to watch. Thanks for the link.
I notice there are some clips on you tube of a Nuno Oliveira playing the organ - is this the same Oliviera or is it a namesake? My father was a concert pianist and organist and I could imagine a rider like Oliviera being deeply musical.
I don't know whether this is correct, but what I have read is that he had a physical impairment or difficulty of some kind as he aged--riding with the head bowed was not a riding strategy, just an effect of that difficulty, which he much regretted. Perhaps others have more information or know the true reason, if I am mistaken.