Using a Tuner

    Tuners are a great aid in determining whether or not your string is in tune.  It is important however to learn what the tuner actually does before you try to correct the string.  If you tighten it too much (which doesn’t take much) you will break the string.  (strings are becoming more and more costly) 

Tuning by ear

Those who have developed the skill can tune their A string to another source (piano, pitch pipe, tuner, oboe player in orchestra) and proceed to tune the rest of the strings by ear using the intervals. 

 Weather problems

Stringed instrument face a special problem when the weather changes.  During the winter months the wood contracts making the peg holes bigger and the strings loosen.  When the weather gets very warm the wood expands and the pegs become more difficult to turn.  In either case if you are not confident that you can tune your instrument without damaging it or the strings you should take it to your teacher for tuning.