In 1989, Daniel Lanois was in the upper pantheon of pop producers, having produced globe-shattering albums like U2’s “The Unforgettable Fire” and Peter Gabriel’s “So.” But Lanois was also a songwriter and performer in his own right, and 1989’s solo debut, “Acadie” finally redressed the imbalance. He joined Deirdre for a short but powerful solo acoustic set in December of that year.