If you needed to make a recording of, say, a person playing the piano, one possibility would be to locate a recording studio with a piano and have the recording made there. Chances are the studio staff has already experimented extensively with microphone selection and placement, and can quickly set up for any kind of sound you might need from that piano.
But what if you have to make a recording of an unfamiliar player playing an unfamiliar piano (or other instrument) in an unfamiliar place? That is the problem I faced when I set up my own on-location recording company. The whole point is that “we bring the recording studio to you.” The trouble is, instead of having months of experimentation to get familiar with the instrument and the layout, I typically would have mere minutes to set up and start recording!
I must admit, I felt pretty nervous about the first few piano recordings I made on location. What if I set the mikes up wrong and end up with a mediocre recording? What if it sounds OK in the headphones on-site but fatal flaws appear when I hear it through the monitors in the mixing studio?
I read up on miking techniques on the Internet, but in a way this made me even more nervous. One knowledgable writer would say to always do some particular thing, the next would say to never do that! I printed out conflicting diagrams of optimal microphone placement for piano. Meanwhile, some writers said to use omnis, some recommended cardioids. Near, far, high, low - it seemed like all of these were approaches that had worked at least once for somebody. But would any of them work for me?-->