In the early 1980s, the period-instrument movement was arriving at full maturity; no longer did you have to worry about whether the gut-strung violins and the boxwood flutes were going to be in tune, and there was solid research behind the new/old approaches to rhythm and tempo. But when Reinhard Goebel’s celebrated Musica Antiqua Köln took on Bach’s magisterial Brandenburg concertos, jaws dropped and heads were scratched across the musical world: yes, they played with admirable precision, but the tempos seemed ridiculous. But the willful oddity of this recording is part of that makes it so compelling — the other part is the precision, and the passion. This shouldn’t be anyone’s only recording of the Brandenburgs, but anyone with an interest in musical debates around period performance will find it fascinating.