Today, multitrack recording is the standard method by which most groups choose to record. The whole point is to capture individual instruments on separate tracks to allow for the greatest amount of control over instrument balance. Great caution is taken to ensure there's no "bleed" from one channel to another. For example, poor isolation can lead to loud snare drums winding up on vocal tracks if the vocalist's microphone is too close to the drummer during a session. This makes the levels between the vocals and the snare more difficult to control.