the use of the various stereo mic techniques has several applications, but is primarily to capture a live performance. the well-known record label "Delos" has a reputation for using minimalist mic techniques and processing for their recordings. sample a few and you will see just how effective a pair of well-chosen and well-placed mics can be. as you know, i focus on small ensembles of classical instruments, so i listen to lots of that kind of stuff. i was on the phone to one of the delos engineers yesterday asking about the way he had mic'ed a flute/harp duo (the glorian duo on their cd "sounds of the seine"). in my process of A/B comparisons of my work with commercial cd's, the glorian duo recording was the sweetest, cleanest things i have run across. the delos guy put them in a nice hall, and used a single coincident pair of neumann km140s at about 5-6 feet out, and let the performers and the natural sound of the hall do the rest. i haven't even heard a james galway cd that is as well done. the delos engineer also recommended a spaced pair of omni sennheiser mkh-20s. one of the most knowledgeable people i have communicated with about this was james boyk, pianist-in-residence at caltech who has spent his life studying the physics of sound and recording - check out the articles on his website - he will only record to analog in a nice hall with coincident ribbons or condensers, with no processing, insisting that you must try as hard as possible to faithfully reproduce what a listener would actually hear. i would not say that this technique is appropriate for most kinds of rock/pop material, but it is certainly one of the most common ways of capturing classical music.