There are very few goals that rival learning to play a stringed instrument with a bow. The violin is a sublime instrument which allows a versatility in play and expression that is unparalleled in the larger instruments. The bow is used to play the violin in the vast majority of cases, although plucking, as with a guitar is done, too.
In order to understand how the bow works, the student must understand the parts of the bow and how they work. The most desired and common natural wood bow is the cambered Tourte Permanbuco bow.
This is not as scary as it sounds. Francois Tourte (1790-1835) developed a bow that was made from Brazilian Permanbuco wood, which has a straight stick that is bent inward (cambered) toward the horsehair which is drawn across the strings to make sound. The horsehair strings are rubbed with rosin (pronounced “Raw-sehn”) which creates friction between the horsehair and the strings. Rosin is the sap collected from pine and other trees. There are many qualities and types of rosin, based on the types of trees and the particular formula used to mix the sap. The friction creates the familiar string sound. With no friction, only a little whisper can be heard from the strings.
The parts of the bow include the stick, the frog, the button and the head. The frog is a mechanism at the base (toward the hand) of the bow that tightens the horsehair. The frog looks like a block of wood and is usually made of ebony wood. The “jewelry” of the bow is on the frog in the form of the silver ferrule. The silver ferrule holds the horsehair and keeps it spread out into the flat ribbon of hair needed to make sound.
The button is at the end of a long screw with more “jewelery” at the end. This screw is used to tighten and loosen the horsehair. The button us usually made of ebony with a silver ring at each end.
The head is shaped somewhat like the bottom of a flatiron. this is where the other end of the horsehair is installed. The head is usually made of mastodon ivory, but can be made of gold or silver, as the final bit of “jewelry” on the bow.
Now, once the bow is put together and the horsehair is installed, the rosin is applied to the bow in enough quantity to make a “puff” of rosin when the bow is applied and drawn across the string. That “puff” means that there is just enough rosin to create friction and to make that lovely sound.
The bow is held in the right hand with the thumb underneath, and the fingers spread across the lower part of the stick. The “down bow” (or stronger sound) is when the bow is moved forward. The “up bow” (or weaker sound) is when the bow is pulled back. The learning process takes care of “bouncy bow” where the tight horsehair “bounces” easily when contacting the strings of the violin. The learning process also takes care of sliding bows, angled bows that never seem to find the sweet spot on the strings to prevent the screechy sound.
There are many techniques with the bow, ranging from how to bring the bow back and forth to create an almost unlimited sustained note, pizzicato, or short notes, rapid acceleration studies or languid, slow playing.
These techniques take time and practice, until muscle memory develops and the strength to maintain the proper position of the elbow, hand, fingers and arms builds up.
And yes it is worth it. I played violin for four years, studying for at least an hour and a half every day. The extra half hour was just from the love of playing.