Thing
The cello is made of wood and metal, and also of varnish and glue. The cello is played with a bow, which is made of wood, metal, and horsehair. Some bows have pieces of tortoise shell, mother of pearl, amber, wire and leather. The bow is not vegan, the instrument probably is.
The cello has a neck and a body. The neck extends upwards from the body, and culminates in a scroll. On old instruments, the scroll is sometimes carved like a female head.
The body of the cello is shaped like a stylized female body. The top and bottom are wide and the middle is narrow. The tail-piece is mounted towards the bottom of the body, and the end-pin is directly below. Taken as a whole, the instrument looks like a fat woman with a long neck and a tiny head. Oftentimes, a cellist will name her instrument and talk to it. My cello is named Bird.
The bow hair is never taken from mares, as they urinate on their tails. This makes the hair weaker. By the time they take the tail off, the horse is dead. Many horses must suffer and die for our infernal habits.
Action
Like a woman, the purpose of the instrument is to make pleasant sounds when it's fondled correctly. The cello is a difficult instrument to play, and a student will take many years to reach a stage of marginal non-suckingness. The technique is only somewhat standardized, and so different teachers teach even the basics in bat-shit loonily different ways.
Playing the cello is a good way to destroy the nerves and joints in one's hand. RSI and arthritis are common. Back injury looms threateningly, and blood runs forth into the street. Playing cello is a thing to do if you are hardcore.
Justification
Playing cello is like the Japanese tea ceremony in that it takes an extremely long time to learn and is more or less useless. Music schools are designed to force people into the profession quickly enough that they don't realize this; the instrument is difficult enough to learn without a vague but persistent sense of discomfort. To be successful, a cellist must spend the day practicing. At night, she can curl up in bed and cry, if desired.
Cellists are sexy. I have seen advertisements which feature pretty women playing cello, which makes them exotic and talented with a possible lesbian subtext. In the movie Truly, Madly, Deeply, a ghost plays the cello. This makes him intense and passionate, yet sensitive and human. It is strange symbolism.
In reality, cellists are boring people. They are also lonely and sad inside. Love them.