What is the grandson of two of the Yiddish theater’s most prominent composers doing at the helm of one of Germany’s premier chamber orchestras? Michael Alexander Willens, the conductor of the Kölner Akademie, grew up davening the Shabbat service as cantor of his junior congregation in Chevy Chase, Md. Today he davens with the Orthodox congregation in Cologne, where he conducts historically accurate performances of Bach and Mozart. As Yogi Berra would have said, only in America.In collaboration with the Dutch pianist Ronald Brautigam, Maestro Willens and his Cologne band are recording all 27 of the Mozart piano concertos, the first complete cycle on period instruments. Brautigam performs on a replica of a Mozart-era fortepiano. Four concertos are available, including perhaps the most challenging of the group, the C Minor Concerto K.491. Willens and Brautigam achieve a transparency that is barely possible, if at all, with modern instruments. Listeners who want to hear Mozart’s music as he heard it should spend some quality time with these recordings.Period instruments never quite made it into the classical music mainstream. Part of the explanation can be found in the late Sir Thomas Beecham’s observation, “Most people really don’t like music—they just like the way it sounds.” The lush, rich sound of modern instruments appeals to audiences more than the spare and sometimes raucous notes of 18th- or 19th-century instruments. The period-instruments movement is partly to blame, precisely because it is a movement, with its own quirks and dogmas. Some period specialists seem to play everything too fast and to revel in jarring sounds. A horrible example in this writer’s view was Harry Bicket’s flat and phraseless conducting in the Metropolitan Opera’s production of Händel’s Rodelinda last year. The classical mainstream, in turn, sometimes dismisses the period-instruments scene as a niche for musicians who aren’t quite ready for prime time.A few first-rank interpreters, though, are at home with both modern and period instruments—for example, the pianist Vladimir Feltsman, who performed Mozart sonatas on a copy of an 18th-century instrument. Brautigam and Willens also are mainstream musicians who choose period instruments for greater musical clarity. They put the slender and sometimes idiosyncratic sound of 18th-century instruments at the service of Mozart’s music, and the outcome is a more transparent performance that makes the composer’s compositional intent clearer than most versions with modern instruments.Hearing Mozart on modern instruments too often is like listening to Shakespeare recited by an actor who mumbles so badly that the puns are incomprehensible. Mozart employs musical puns as surely as Shakespeare used poetic ones. A striking example occurs in the final bars of the C Minor Concerto, when Mozart slips from common time into a playful 6/8 meter. The piano plays the same chord twice in which the decisive note is written first as D-flat, and then as C-sharp. On the piano these notes are played with the same key (that is, they are enharmonic equivalents). But they have different musical connotations. The D-flat points downward toward subdominant harmony; the C-sharp points upward to a cadence on the dominant. Mozart repeats the gesture with G-flat and F-sharp, using the F-sharp to set up the final dominant on G and the concluding cadence in C minor.This is more than an inside joke on the part of the great composer; it is a stunning bit of musical sleight-of-hand that creates and resolves an ambiguity about the direction of the music. On hearing this for the first time, Beethoven turned to his pupil Ferdinand Ries and sighed, “We shall never think of anything like that!” More clearly than in any of the dozens of renderings I have heard, Willens and Brautigam illuminate what Beethoven found so special about this movement.***Tablet’s classical music critic David P. Goldman interviewed Maestro Willens via Skype. He spoke to us from his home in Cologne.Maestro Willens, one of your grandfathers was Alexander Olshanetsky, a famous composer for the Yiddish theater and the musical director at the Concord Hotel in the Catskills. Herman Yablokoff, another mainstay of the Yiddish theater, was your other grandfather. That’s an unusual combination of Jewish as well as musical yichus. Can you say something about your relationship to Judaism?I grew up in Chevy Chase, Md. I attended public schools, but I had Hebrew school three times a week. I became cantor of the junior congregation of my synagogue, and I used to daven the whole Shabbos service every week. After my bar mitzvah, like so many other Jews of my generation, I drifted away from interest in the synagogue. We were a wealthy community, and I felt uncomfortable with the High Holidays as a showcase for one’s wardrobe. So, I did what most teenagers seemed to do and got very far away from everything Jewish. But when I moved to Germany, I got back in touch with Judaism. The first time I went to Shabbos services at the synagogue here in Cologne, I burst into tears. It was the same melodies, the same prayers, and it was a real feeling of coming home. There’s a fairly large Jewish community: a lot of people from Israel, a lot of Russians who don’t know anything about Judaism but are learning. And there are some families who came back to Cologne after the war.Here in America, we hear many worrying things about anti-Semitism in Germany. This was highlighted recently by Günter Grass’ attack on Israel as a bigger threat to peace than Iran. What is your perception?Personally, I’ve never felt any anti-Semitism in Germany, although one reads about it. I live in Cologne, which is a cosmopolitan city. It might have been different if I were in the east of the country, for example. Of course, one never meets anybody whose family were Nazis. I can’t believe that none of them had Nazi connections. There’s joke about the German version of Alzheimer’s, namely Waldheimer’s. You can’t remember anything that happened between 1939 and 1945.Recording all 27 Mozart piano concertos is an enormous undertaking. When do you expect to complete the project?We have two CDs out and a third scheduled for July. The plan is to issue a new installment every July and finish in 2015 or 2016.There’s a famous article by Carl Schachter on Mozart piano concertos, emphasizing their quirkiness as opposed to the “divine gift for the middle of the road,” which is so often attributed to Mozart. I hear a lot of Mozart’s strangeness in your version. How do original instruments make this more audible?You get more of this quirkiness because of the imbalance in the period instruments; the rawness of the winds, the gut strings, the overall transparency of the sound. It’s very difficult to get that with modern instruments. You have a better chance to bring such things out given the nature of the instruments. I come from a modern performance background. At Juilliard, I was a triple major in double bass, composition, and conducting. I was introduced to period instruments by Albert Fuller, a harpsichordist at Juilliard. Once I experienced hearing and playing Baroque music with period instruments, with their greater transparency and lower pitch, it was hard to go back. The slenderer sound takes away a layer of melted cheese and lets the voices come through much more clearly.There are some musical moments, for example, the coda of the third movement of the C-minor concerto, which come out much more clearly in your version than in any other I’ve heard. I hear a clear difference between D-flat and C-sharp, for example. Part of that is a matter of phrasing, but part of it seems reinforced by the instrumentation.In part that has to do with tuning. Modern orchestras use equal temperament [in which all intervals are tuned to have exactly the same ratio of frequencies]. Eighteenth-century orchestras had subtle differences in temperament which allowed for a more differentiated tone color. Mozart was aware of this as a keyboard player. We have used historical temperament along with historical instruments. The result is that the shock of key change is greater. There is also a striking difference between keys. On the first CD, we have concertos in E-flat and A major. The brightness of the A major and the grandeur of the E-flat are much clearer with period instruments. C minor has a darker quality that is accentuated by the instruments and the temperament. And in the Concerto No.25 in C major, the military quality of the trumpets and drums is much clearer than with a modern orchestra. Tone painting is very important to 18th-century music.Does it help to be Jewish to conduct Mozart?I don’t think it hurts. Mozart was a very worldly person; he was something of an enfant terrible, entertaining royalty, but standing up to them. Worldliness is a great help to interpreting this music. But I would add that living in Europe has been an important help. One becomes aware of how deeply the music is wedded to language.***Like this article? Sign up for our Daily Digest to get Tablet Magazine’s new content in your inbox each morning.David P. Goldman, Tablet Magazine’s classical music critic, is the Spengler columnist for Asia Times Online, Senior Fellow at the London Center for Policy Studies, and the author of How Civilizations Die (and Why Islam Is Dying, Too).