First off let me say that I play with gut strings on my G and D strings. I used to play guts years ago, abandoned them for steel, then after many attempts to get back on the guts ditched the steels again for a gut set up. One of the reasons it took me so long to get back on the guts (though I love the sound) was that I had to play them for at least a few days before my ear would get adjusted to their particular sound, intonation, overtones, percussion etc. I would put them on and decide that they sounded beautiful in some aspects but totally out of tune and then ditch them for the steels. Recently at a performance, a musician near me kept complaining that something was out of tune. I was the closest and I was fairly certain he was referring to me. He kept shaking his head perplexed in between tunes, scrambling for a tuner etc. I experimented by using lots of open strings whenever I could to see if it changed his perception but he still seemed unhappy. Later in the performance he was fine and the music was beautiful. This has happened to me every once in awhile and I just started to think about it a little more in depth. The obvious would be that I was in fact playing out of tune which we all do time to time. But this reaction, often from classical musicians, would also happen during pre-performance tuning as well, even with an electronic tuner, even using the same tuner. My theory is that it might just be that some people are just not used to the sound of the guts and find the overtones and tonal characteristics a little confusing. It doesn't happen on the two existing steels, only the guts. Has anyone experienced this before and what do you think of my theory?