What kind of hat does Carlos Santana wear?

Those are Nepalese hats based on Tibetan design. Wool with lining and embroidery.
They were a standard import shop item before the rise of the childish animal hats.
Now, they are hit and miss.
The shops near Naropa University are usually good for a few, as are the shops with a more religious bent over a hippie bent.

Also, http://www.ebay.com/itm/C597-Tibeta...oidery-Boho-Round-Cap-HAT-NEPAL-/131052497835

 

Very close in cut are bohkarian hats.