Transcending Music


Ok, so when you mention 15 to 20 instances, what does this imply exactly (sorry I'm not familiar with PLAY at all)? In other words, is it something like this: Violins 1 and all of its art's in one instance of PLAY? Also, 15 - 20 instances uses how much RAM on your system?  

To add: how does one go about switching between patches within an instrument articulation? Does it use keyswitches as well? For example: going off a demo vid, let's say you are in 1st violin, short tight.I see there is a Xfade patch for ****cato to Marc and another patch below that Stac to Marc. So how would you switch within a composition?   

Yea loading times I suppose are the trade-off for certain libraries, depending on the size.