If a string section, an acoustic guitar, a drum overhead, or a piano was recorded with a small-diaphragm condenser at a serious studio in the last forty years, it was probably a Neumann KM 184 (or its predecessor the KM 84). ~$900 each, almost always sold in matched pairs.
Small-diaphragm condensers (SDCs) capture transients faster and more accurately than large-diaphragm mics — perfect for picking up the attack of a guitar string or the “splash” of a cymbal. The KM 184 is the SDC most engineers reach for when the source is acoustic and the room is good.
The KM 184’s top-end is famously musical — a slight presence rise that flatters strings, woodwinds, and acoustic guitars without sounding harsh. It’s the mic engineers buy when they want a stereo pair that will work on anything acoustic for the next thirty years.