A few weeks ago a studio engineer (on observing the ritualistic rosining of my bow hair) asked me what rosin was. It suddenly occurred to me that I knew very little about this substance which has aided my violin and viola playing for over 30 years!
Rosin derives from resin, a globulous liquid found in trees. The rosin used for stringed instruments is solid and usually derives from pines (mainly conifers). It is gained by heating up the liquid resin until a chemical change takes place and can be a variety of different colours (some amber, others a dark green).
The main purpose of rosin is to increase the friction of the bow hair. Everyone who has played a stringed instrument has (at one time or another) taken a bow with brand new bow hair and ran it along the strings. The bow skates around and produces virtually no sound at all as it hasn’t any grip. It’s rather like the sticky powder weightlifters cover their hands in before attempting to lift their weights. In fact, if we were to place a single bow hair under a microscope, what we’d see would be hundreds of tiny ‘teeth’ which cause the string to vibrate. The rosin helps the teeth to pull on the string more effectively.
I’ve heard many beliefs concerning rosin. Some players buy expensive cases of it with fine pigments of gold mixed in and swear it has a transformative effect on their sound. Personally, I’ve always been content with the cheapest rosin available and shall continue to be unfussy about this particular aspect of playing. What I can say is that it’s always worth cleaning the rosin off your strings at least fortnightly. This is because the rosin becomes compacted on the string, causing it to resonate less clearly and accentuating ‘wolf’ notes and ‘whistles’. Do this with a clean duster – no white spirit or other chemicals are needed at all. It’s also worth cleaning the body of your instrument every day to make sure the rosin doesn’t start to take hold on the varnish (particularly under the strings). It can be very sticky and discolour the varnish (marring the appearance of the wood), so again gently remove with a clean duster. Once it has taken hold and become suffused into the varnish it may be worth showing it to a luthier to see if anything can be done to remove it (in the case of an old instrument don’t use any polishes which may erode the varnish itself).
Some players swear there is a distinct difference between cello and violin rosin. They say that the cello rosin is stickier and less suited to the violin or viola. One folk player says he uses it to create a scratchier sound, yet other players have got the two types mixed up and claimed they couldn’t tell which was which! As I haven’t any experience of cello rosin, I can’t really comment, but if you have the wrong type, don’t worry. . .rosin is incredibly cheap so just go out and buy the right kind!
