I know that I have talked about acoustic guitar steel strings and changing them and how to, etc. However, I failed to address this more fundamental question in that post.
The answer is, yes, you need to change strings even if they are not broken: whether they are new ones that you installed on your guitar months ago and stored away your guitar, or, those that you have played and played and they, fortuitously, have not broken.
New strings and not played
Many people have more than one guitar. They feel that if they change the strings on an instrument, put it into storage, and whenever they take it out, the strings should play and feel brand new.
Logical in theory but not true in the real world.
The fact is that once strings are put in tension they will go dead from being under tension for extended periods of time – played or not played. The sustained tension stretches them out and deadens them. Unfortunately, you NEVER leave an acoustic instrument without strings (not necessarily tuned up to pitch, but tuned half a step down or a full step) on the neck. That would be bad for the guitar itself.
Old used strings and played to death
No matter how clean your hands are, every time you play your guitar, know that you are depositing some DNA on the strings (and the fretboard too). The continued deposition of DNA – body oils and skin – deadens the strings. Old strings sound bad, are difficult to get in tune, and can break unexpectedly.
That old devil, Humidity, too, plays a huge part in the degradation of strings. Metal+Moisture=Rust!!!
The magic rule is to change strings every 100 hours or 3 months—whichever comes first – if you don’t play four or five hours daily. In that case, you need to change strings monthly.
What to do to lengthen string life
Simple things like wiping your strings before and after playing go a long way in lengthening the life of your strings. But then I have seldom seen that patience in guitar players.
There are also conditioning lotions for strings. You can apply them and they work – somewhat. The flip side is the added expense. The same thing is achieved – maybe better – by wiping your strings.
Also, in the market there are a variety of pre-coated strings and treated strings that do not let the body oils/material deposit on the strings. And if it all it does get deposited, it is unable to affect the strings. The downside? These strings are easily four times the price of ordinary strings!
To get the complete low down on strings, also read: