Why is it so easy to tell the difference between live and recorded music?

I posted about this a while ago.  To my ears, there is very rarely a doubt.  Sight unseen, approaching an area where music is being played, without prior knowledge, I can very reliably tell if "it's live or if it's Memorex";-)

I've always thought that, on a subconscious level, your brain goes down its "survival checklist" when it encounters new sounds. One of the questions it asks: Is what I'm hearing able to cause physical harm? Is it real? Is it close? Etc. A marching band passing your open window leaves no doubt as to its potential for physical harm. Any stereo you are likely hear just won't have the same cues.   

I’m in the same boat as Trelja , natural tone and timbre seem the limiting factor for many systems/components. This is the bottleneck more so than dynamic range which is the next most limiting factor IMHO. The addition of a certain hardness or "edge" signature just labels the sound artificial or canned more often than not. These are the two main culprits but there’re others that exist.
Charles

If you mean live music that is amplified like rock music, then the live sound you hear may be from the PA system which gives it a very forward, often one dimensional sound. Also the reverberation may affect the sound (many greatful dead recordings suffer from this). When audiophiles say live music is the ideal I often disagree unless they are referring to classical or chamber or choir music. I enjoy rock and blues concerts but find that many concerts have pretty bad sound due to the location (eg basketball arenas) but also because everything is pipped through the pa loudspeakers which to me often loses the separation and texture. When I played in a band I loved hearing the drums and fender amp directly when we rehearsed. Going the the PA system usually degrades the sound unless great care is taken by the performers and crew. 

Back in the 1960s AR marketed their AR3a loudspeakers with a live vs. recording demonstration.  A string ensemble, solo violinist or guitarist would play a piece and at some point the sound would be switched to a recording.  Listeners would then be asked to comment whether they could tell when the switch took place.  The majority of listeners could not accurately detect the switch over.  A key element of the demonstration was the special way the recordings were made.  They were made either outdoors or in anechoic chamber to avoid the "double acoustic space signature" effect during playback.