Knowing whether or not you need to change your strings on your orchestral instrument can seem complicated, but it's actually quite easy!
First you need to identify whether or not your old strings need to go. The most obvious sign of a worn out string is its appearance. A brand new string is a bright silver color, and if you look closely you can clearly see that the steel winding on it is neat and in tact. An old, worn out string will be a duller silver, and may even be corroded in some areas (this will be apparent by a rusty or dark gray color on some areas of the string). Another visual sign of a string in need of a change is if the steel winding around the strings has begun to unravel, and small steel windings are falling off of it. If you see any of these characteristics on your strings, it's time for a new set.
A less obvious sign that you need new strings is the sound and responsiveness of your current set. Oftentimes, a string player will become frustrated with the sound they're producing and blame it on technique or level of skill. More often than not, the source of their problems is in their strings! While playing your instrument, if you feel that the sound coming from your instrument is dull or muted, or that they're slow to produce sound when your bow comes into contact with them, check with your instructor or come in to the store and ask about replacing your set of strings.
After you've determined that you need new strings, it's time to figure out what kind you should buy! Depending on what instrument you play, strings can get pretty pricey, so it's important to know for sure that you're buying the correct and best strings you can. If you're a beginner, D'Adarrio has many different affordable and sensible options, such as Prelude, which is very common for students to use. If you've been playing for a few years and want to improve your sound, Dominant strings by Thomastik Infield are a great step-up brand for violinists and violists. For cellists, a great string to upgrade to from Preludes is Helicore, also by D'Addario. If you have any more questions about what strings would be best for you, feel free to come into the store and we can match you to the perfect set.
Now you have all the tools you need to identify when it's time to change the strings on your instrument. Good luck, and happy practicing!