It's small and comes in a small box, but the importance of this particular violin accessory, rosin, is considerable.
So, you've purchased your child a violin. Most likely, whether you purchased the violin from a private party, online, or from a brick and mortar violin shop, you now have a violin and violin bow in a violin case. That's a great start but, unfortunately, only the beginning of acquiring the most essential violin accessories necessary to providing your child the most complete playing and learning experience possible.
One of the small but very important accessories you can purchase for your child is violin rosin. Actually, "important" doesn't go far enough. Violin rosin (or rosin for the viola and cello) is essential. It's so vital that even if you have a bow and a violin, your child will not be able to play the instrument without rosin.
What is rosin? Rosin is a small, smooth and semi-transparent round or rectangular cake that fits in the palm of your hand. It is made from the tree sap of various conifers, like pine, that is hardened and varies in color from light amber to very dark brown. Rosins are now available in a synthetic blend made for those who are allergic to tree sap.
How is it used? The student should tighten their bow to the appropriate tension for playing and then rub the bow hairs back and forth along the cake of rosin. Typically, a bow only needs a few passes across the rosin once the hair has been broken in but a freshly rehaired bow may need quite a bit more passes across the rosin to achieve the desired effect. The rosin is a sticky substance that adheres to the bow hairs and allows the bow to better grip the violin strings by increasing friction when drawing the bow across the stings.
There are different grades of rosin available for beginners, intermediate players or professionals and rosin does differ between instruments. The smaller string instruments like violins and violas typically require the lighter rosin, while cello rosin tends to be darker colored. The quality of rosin is dependent on other substances that have been added to the mix that modify not only the color of the cake, but also the friction properties. Rosin ranges in cost, from anywhere between $3 a cake to $48 for the higher-end professional grades.
It's always best to ask the advice of a professional, whether you're purchasing rosin at a violin shop or an online violin store that sells violin accessories like rosin. You may also ask your child's teacher for his or her recommendation of which grade of rosin is best for your child.
Just remember: each time the violin is played, rosin dust accumulates on the strings over time. It is wise to purchase string-polishing cloths to wipe away excess rosin from the strings every so often.