Before the session
Joni Mitchell tuned every guitar to its own open tuning, so the first hour of a session was spent on strings rather than songs.
Engineers learned to leave that hour alone. It set the room, the tempo of the day and which instruments would be in reach.
Choosing the room
A dead room keeps the voice close. A live one lets the guitar ring into the corners and come back a little late, which is its own kind of harmony.
Microphones
One ribbon above the sound hole, one condenser near the twelfth fret, and a single valve microphone for the voice, set a hand apart from the lips.
Tracking
Most takes were full performances. Stopping to punch in a line broke the thread of the tuning and the song together, so the band played through.
When a take was close, the next one was usually worse. The rule became three passes, then a walk around the block.
Headphone mixes
Every player had their own mix, and every mix had more of the voice than anyone admitted in the control room.
Mixing
The mix was a matter of taking things away. Reverb was the room itself, and anything added later had to sound as if it had always been there.
Tom Waits once described a good mix as the moment you stop hearing the speakers. That was the only test that mattered.
Tape and air
Half-inch tape at thirty inches per second kept the top end open. The hiss was part of the record, like the paper under a drawing.
Afterwards
The reels went into a cupboard labelled with the date and a single word for the mood of the day. Years later, those words were still right.
Some of the best songs on the record were the ones nobody planned to keep.