Hi, so I just opened up my guitar case from a gig last night, and I noticed that every time I strummed it after I tuned my strings, it would instantly go extremely sharp. Is there any explanation for this? I haven't done anything different since I got it a couple months ago.

I heard that humidity could cause a role in this. Last night, I was in a very warm, super humid room, and now I keep it in my cool, dry house.

So what could I do to fix this? My other band is having a rehearsal tomorrow and I don't want to show up with a severely out of tune guitar!!

Last edited by ploxxies at Nov 20, 2013,
unless your guitar has a floating bridge you can just tune it again no problem
im sure someone there has a tuner and if not you SHOULD get one

and yes hot and cold temperature can affect it but not too much unless youre going from frezing cold to really warm
if you havent changed the strings since you got it that also affect tuning stability
Supersac has some good points. Maybe your strings are too old already and you need to change them. In the case you have a none floyd rose guitar, remove the strings for a couple of hous (or half a day) for the neck to relax, then put new strings and set up the guitar from scratch. That should solve the problem. In you have a floating bridge (and you know how to do the next step) take it out, clean the dust and rust. Oil the knives edges, oil the tuning pegs and every little pice that moves. Replace your springs for new ones (just in case), put if back in an set up the guitar. Good luck!
I dont understand how people go months without a string change, I change mine every other week.

So yeah, get rid of those dead strings and you'll most likely find your truss rod is out of whack.
Thanks for the answers. I have a floating trem, so I guess I'll replace all my strings. I haven't changed them in a long time.
What you describe is a classic example of a poorly cut nut. The slots in your nut are either cut too narrow or have some rough edges that the strings catch on. What happens when you tune your guitar you are pulling the string tighter... if it doesn't pass through the nut the way it is supposed to it catches, and the string tension between the tuner and the nut is greater than the tension from the nut to the bridge. When you start playing, the movement of the string allows it to slip through to equalize the tension and consequently goes sharp.

You can take it to a tech to get fixed or you can fix it yourself. The cheap fix is to go to a hardware store and get a set of torch tip cleaners. They are tiny wire files of various thicknesses and cost $3-5. Select the size just slightly thicker than the string and run it through the slot a few passes. Then lubricate the slot and string with pencil lead (graphite). Other lubricants like chapstick also work.

Whatever you do, don't start wanking on the truss rod without understanding what is going on with your guitar. It is extremely unlikely that your truss rod has anything to do with your tuning problems. I am amazed how many people have no clue what a truss rod is for, and yet give advice to start cranking away on it.
Last edited by stormin1155 at Nov 22, 2013,