Nothing can kill a great guitar faster than dry air. Dry air makes us sick and dry air destroys our guitars. Wood likes to be moist — but not too moist — and in my experience a guitar can handle too much moisture much better than it can handle too little water in the air. Dry wood tends to crack. Moist wood tends to swell. Keeping my guitars properly “watered” is one of the ongoing dedications of my day — and checking the water content of the air is as regular a practice for me practicing Jimmy Bruno’s Five Fingerings.