Recording live is when the singer delivers her recording while the band is playing. There are different methods of separating the singer from the band to avoid the guitars and drums spilling into the vocal mic. For example, the singer may record in a separate room or from behind some baffles. Both techniques partially isolate the singer. Recording live has multiple benefits. You save time on recording, because everything is captured in one take. Also, live recording can create a more organic and natural sound, especially when there is visual interaction between musicians, permitting them to use the visual cues they’d use when performing.
An isolation booth is a sound-proof, acoustically treated environment, typically the size of a large closet, in which the singer records her performance. An isolation booth is designed and built to minimize sound reflections and to reject sound from outside, enabling you to record the vocals without any interference. The benefit of an isolation booth is that the singer can focus solely on her performance and the sound is typically pure and controlled. One drawback is that some singers find the experience sterile and too different from the act of performing with a band.
This approach involves recording multiple takes of the same vocal and layering them, for a thick, full sound. It is convenient for singers who want to add extra parts. Harmonies, backing vocals and counter-melodies must all be multitracked, as it’s impossible for one singer to record multiple takes at once.
Recording line-by-line is an exacting process where the singer focuses on a small section of a song and sings it over and over until she gets a take she’s happy with. Then she moves on to the next section. This approach typically makes for an accurate and technically proficient recording, but can be exhausting for the performer. It may also be quite expensive, as it requires more studio time. Another drawback is that the finished recording may sound disjointed, especially if the singer takes extended breaks between takes. You can combine this technique with recording live to correct mistakes captured in the live performance.
This is an old technique that modern producers may occasionally use to capture a “retro” sound. By placing a microphone or microphones around a room and recording live, you capture the ambient sound of the performance, rather than the specific sound of a vocalist. If done carefully it can create a moody, laid back vibe. But you have significantly less control over individual sounds and if there’s a mistake, you have to start over.