Following basic tracking in France, Buckingham, Christine McVie, and engineers Richard Dashut and Ken Caillat (studio allies since Rumours ) became the chief architects of Mirage. Fleetwood, says Lindsey, is more of an overseer. "He has a real good sense of taste. If something starts to go even a little off, he'll recognize it quickly." Caillat estimates Nicks's contribution to be about ten percent of recording, most of it during the sessions in France. "Stevie didn't come down a lot," admits Buckingham. "She was in the studio, aside from France, maybe a total of ten or fifteen days."
That helps to explain the subtle shift in vocal chemistry on Mirage. Fleetwood Mac saw the introduction of an established, distinct vocal relationship in the Buckingham-Nicks duo, a sound that continued to dominate the band's vocal blend through Rumours. "Stevie and I both had a nasal tendency that seemed to fall in the brass range," says Buckingham, "and Christine added a woodwind sound to the whole thing." There are moments on Mirage that recall that mix, but in most instances the actual singers are Buckingham and McVie. "We've learned to sing like each other," chimes in Christine, "but that's come about over a period of eight years. When I first started to try and sing with these guys, they were so locked into each other's sound, I really felt out of in. Now we automatically fall into it."
How well they do that is exemplified by the rich voices that float through Mirage. A comment on a particularly effective descant, behind the chorus of Buckingham's Book of Love, elicits smiles from the author and his keyboard partner: It may sound like one of Nicks's better moments, but all the voices are Buckingham's. "On some of the vocal parts", says Christine, "Lindsey sort of slowed the track down and sang the part. When it was speeded up it sounded like Stevie. I listen to Book of Love and I think I'm on it as well."