Topmusicanswers
It may be that it slipped out of the nut or that the groove in the nut is cut in too deep (a steel E string may cut itself deeper into the nut when tuning) or that the nut has cracked and the string slipped into the crack. Or the nut is displaced and the string action too low in consequence.
Why does my E string sound out of tune?
Most likely it's riding too high on the nut, and as you depress it onto the frets, essentially you are bending the string slightly sharp. Proper setup should take care of this. This is very common on most makes of guitars. The low E string can be compensated by changing where the string touches the saddle.
Why does my a string sound weird?
A low action height is when your guitar strings are closer to the frets. When the action height is too low, the strings will vibrate against the other frets when you play something. ... If you notice your strings buzz or vibrate in a strange way when you strum them, you may want to check your action height.
Why does E chord sound bad?
Whenever you've got intonation set properly but one or two lower-position guitar chords sound out-of-tune, it's almost always a nut issue: The nut may be too high, which makes the action higher than it should be at the nut.
