1. Castrato - included for obvious reasons. The most famous of the castrati lived lives of luxury, but only a small percentage of those subjected to the horrendous operation became professional singers. Why the big fuss about this gruesome voice type? Friedrich Brodnitz explains in "The Age of the Castrato Voice":
The castrati sang with the lung power of an adult and the larynx of a child. This enabled them to spin out long musical phrases in a single breath. With growing age their voices slowly dropped from soprano to alto, but they always maintained a peculiar character that differentiated them from the typical timbre of normal adult male or female voices.
2. 18th-century violin-string maker - With the beauty of the violins built in Europe in the golden age of violin-making, it is often forgotten that somebody had to create the strings that would make the instruments sound in an age long before metal strings were invented:
Fancy hanging about in an abattoir and pulling 9 metres (30 feet) of warm intestines from a barely expired sheep? Hard to resist, isn't it?
It gets better, though. How about separating the hot guts from the fat and then kneading the offal to milk out the stinking sheep excrement? I know, it's too good to be true. You will also have to soak the guts in cold water for a while, strip and crush them, fumigate them (with the added delight of the horrid stench of burning sulphur) and then twist them into strings. It's not all fun, however – you only get to do it for 12 hours at a time!
Of course, working conditions of string-makers have improved greatly since those times and companies such as E. & O. Mari specialize in gut strings made still from traditional materials (yuck!) and methods (eww!).