Guitar strings, just like the soles of our shoes, wear out with much use. If this happens, the worn out strings will tend to sound less bright, and your guitar will lose intonation more quickly. That’s the reason why you need to change your strings regularly, moreso if you are a professional guitar player and you often use your guitar with guitar lesson software.For professional guitarists, you probably use your guitar more than 4 hours a day with practice and gigs. That’s why it’s advisable for you to change your guitar strings at least every 2 weeks. After all, the price of strings is nothing compared to the amount that you will lose from your gig for example, if you end up with a broken guitar string during a performance. For beginners, I guess it’s okay if you change your strings at least every 2 months instead.