Thoughts on the most difficult instruments for speakers to reproduce?

Digital is not always bad, so with the proper set-up we can get quite acceptable quality, meaning a lot of instruments sound very acceptable. Of course, the rest of the system should support such elevated quality levels as well. Nevertheless, even with the current high end audio, it is still easy to differentiate life from recorded music. (analog and/or digital). It al comes down to what we find acceptable, which is personal. Some people are prepared to go further than others. I believe that the sound of certain instruments is harder to reproduce using audio equipment within a certain price class. To reproduce the sound of certain instruments properly, it may take a higher investment, perfect room acoustics and so on.... (however, I (and you) believe I (we) can easily detect if what I hear if life or recorded music, so...the engineers are not yet done with it...)

@vinylfan. Agreed, even with the best equipment, a poor recording won't sound good, however too often people blame the recording whilst it is the equipment not capable of reproducing what's on the recording. Not many speakers will be able to reproduce the dynamics of percussion to the full extend. Most rooms will not allow to enjoy such dynamics to the full extend either. It's always a bit of a compromise I guess. On the other hand, using higher end (not necessarily the highest end) audio equipment will indeed often reveal that the recording wasn't done properly.