A Very Particular Set of Skills
Yes, the title is shamelessly lifted from Liam Neeson's character in the movie Taken.
No, the particular set of skills being addressed aren't the sort that a vengeful FBI agent would have (though that would come in handy).
What a professional musician brings to the table is a command of his/her instrument, and the ability to communicate and connect with the emotions of his/her listeners. It takes decades to learn, both physically and mentally (you never hear of someone who started playing in their 30's winning a position in a professional orchestra). Auditioning for an orchestra is a lesson in humility and masochism since a slew of people (depending on the position, around 20 - 160+) are all vying for the lone position available. Performing also takes its toll - although it doesn't seem all that physical, the repetitive nature of playing a string instrument or holding a brass instrument for 25+ years wears on a body. All of this doesn't mean that we don't love our jobs or need to whine, it's just that, when you look around at your colleagues in an orchestra and see and hear them kicking ass night after night and you know everything that goes into making that kind of player, plus adding the usual life issues that make a challenging job more challenging (car problems, sick kids, catching what your sick kids gave you, etc.), you marvel at what dedicated, highly trained people can and will do to 'bring it' every performance.
The next time you read that orchestras are 'dying out' or that musicians need to take a 40% pay cut to keep their organization afloat, imagine how much more could happen if the people running those organizations 'brought it' with as much focus and consistency as their musicians. Or Liam Neeson.