Guitar strings are a pain to change, especially when you have to change the whole set. And guitar strings should be changed, say, every twenty-thirty hours or so of play (in my humble experience). Oil and sweat from your figners tend to dampen the strings’ response. This “response decay” is especially obvious on the kind of wound bass strings used on accoustic and classical guitars. To lenghten the life of strings wipe them down after use and always make sure your habds are clean before playing. Also wipe the fingerboard clean.
Here’s an interesting question/answer article on strings from Music Centers.
