So, I haven't played my bass in over a month, thanks to being too busy with university, and when I went to play it for some reason the frets closer to the head of the bass wouldn't give a clear note on the E or A strings, but they would most of the time on the D and G strings. They just make this gross noise that sounds like it's muted and I'm worried the neck of my bass is warped or something. has anyone ever had this problem, or know what might be wrong? I'm a beginner at this, and this is my second bass. The first one broke last summer, and I really can't afford a new one again. Please help me out if you can!