In celebration of the 325th anniversary of the birth of Thüringen’s most famous son, two musically active Back Bay churches threw open their doors all day on March 20, this first fully spring-like weekend of the year. First Lutheran, whose celebrated Richards, Fowkes organ, op. X, will mark its first decade this December, sponsored a solid and skillfully programmed octet of half-hour organ recitals. The concerts drew good audiences; many faces from the morning were still to be spotted at the early-evening double bars. Entry was free to all. Parents with strollers, a few score-toting devotees, Bach-aware preppies, and people who don’t usually go to  hear classical music — the changing crowd in the pews were a pleasingly mixed lot.

From 10:30 that Saturday morning, about 100 kiddies and parents sat backward in the pews, facing the splendid organ on its balcony and a projection screen. Sharp-witted French organist Guy Bovet wrote “Peep the Piper,” a 30-minute multi-media presentation for children from age six on up. It uses CD-ROM projection of Bovet’s amusing drawings, a narrator, and a wide-ranging score demonstrating what the organ can do. Twelve-year-old Oliver Jay narrated from above, standing not far from First Lutheran music director Bálint Karosi at his console. No child was left uninformed, to paraphrase a former fearless leader, and FLC parishioners handed out little wooden recorders to all the children as they were leaving. The same large screen traveled to the front of the church, where it allowed the audience a view of the organists at work. This has been among the successful innovations at First Lutheran, as in a few other churches around the land. The video camera and screen personalize musicians who formerly played in visual anonymity.

Mr. Karosi, who was the motive spring behind the day’s well-organized succession of events, opened the all-Bach concerts proper with a sonorous and finely paced presentation of the Fantasia & Fuga in g, BWV 542, following this big statement with two of the poetic Schübler-Choräle: Meine Seele erhebt den Herren, BWV 648, and Ach, bleib bei uns, Herr Jesu Christ, BWV 649. These performances convincingly demonstrated just a couple of Bálint Karosi’s sides. He is a highly accomplished clarinetist, harpsichordist, and composer whose many activities in Boston have already made him one of the city’s most effective audience builders and performers. His recital came to an end with a dancing and finely architectural flight through the normally rather massive Passacaglia in c, BWV 582. It left the big audience entertained and audibly anticipating whatever portions of the ensuing seven recitals they would attend.

But first, at noon, First Church’s cheerful noontime lunch below-decks (lasagna, salad, a Baroque-decorated German chocolate cake) fed a nearly full house. Afterward, Emmanuel Music’s brilliant Nancy Granert extracted enchantment and jeweled detail from the spare, bardic pages of the Canzona in d, BWV 588, then lavished the same loving attention on the longer and more extrovert 6 Partite sopra O Gott, du frommer Gott, BWV 767. In closing, she thrust the arpeggioed opening flourishes of the Pièce d’orgue in G out into First Lutheran’s airy, resonant nave with a special metrical clarity that lent the lyrical middle voices a gratifying declamatory vigor.

The quick speech of this instrument’s Pedal and of the lower manual pipework could be said to be among the nicer hallmarks of mechanical-action organs in general, but voicer and co-owner of the firm Bruce Fowkes has demonstrated stand-out ability at pulling off this technically quite difficult feat. This holds not only for the big reeds, but also for the Prinzipal and Flöte (Bourdon) ranks. All speak together and crisply, without the unwanted artifacts of forced attacks. A long column of air extends from the windchest through a pipe’s foot, past the languid (comparable to a recorder’s sound-producing lip and airway), and up into the vibrating length of the pipe. When this column is greater than about 2 meters in length, there can be a delay until all of the carefully controlled volume of air begins to vibrate in a stable, musically useful way. The Richards, Fowkes organ’s astonishingly articulate speech in the lower ranges, despite low wind pressure, challenges organists to phrase with a lucidity of gesture and voice definition that are not at home on electric-action instruments.

Saturday lunch was in a comfortable state of digestion when Worcester-based Frank Corbin demonstrated yet more facets of the Richards, Fowkes. His Prelude & Fugue in c, BWV 546, evinced joy in the big, minor-key sweep of a Bach statement in large format. His resigned, gentle O Mensch, bewein’ dein’ Sünde groß, BWV 622 (Orgelbüchlein) unfolded with measured gravity. Two of the famous group of Leipzig-Choräle – Von Gott will ich nicht lassen, BWV 658, and O Lamm Gottes, unschuldig, BWV 656 – reveled in the contrast possible within the modest but ample registrational palette of the organ. The close of the latter chorale transitions into a bold 6/8 burst of full-throated majesty, which Mr. Corbin pulled off to good effect.

Next to ascend to the organ balcony was Christian Lane, who sports many an organ-world hat in Boston and at Harvard. In his businesslike Prelude & Fugue in C, BWV 545, the generous, ever-changing audience took in yet another of the many flavors of “full organ.” He observed a modern-era Bach performance tradition in pairing, and allowing the audience to savor in comparison, Allein Gott in der Höh’ sei Ehr’, BWV 662, and the Trio super Allein Gott in der Höh’ sei Ehr’, BWV 664 (both Leipzig-Choräle). In early recordings, German organists such as Hans Ander Donath (1941 Reichsfunk tapes, Frauenkirche, Dresden) and Helmuth Walcha (early stereo, Alkmaar, NL) delighted in contrasting Bach’s exquisite, very diverse settings of this chorale. Mr. Lane’s grand, masterful approach to the Prelude & Fugue in a, BWV 543, ended this half hour. Not many of the big concert works feature so active and wide-ranging a pedal part from one end to the other. When the Pedal does fall briefly silent, it is only to tease listeners with the effective tension of its absence. Mr. Lane’s registration favored dark hues that, in another musical context and on an organ that enunciates less unambiguously, would have descended into stentorian murk. His sure pacing and care in minutely aligning Pedal speech with that of the manuals — quite a stretch, if you’ve never tried this! — were unalloyed delight.

The well-traveled organ shoes of Church of the Advent head of music Mark Dwyer must no doubt often make the change from 20th-c. American-Guild-of-Organists’ concave-radiating pedalboards to their flat, straight predecessors. At First Lutheran, the Pedal has today’s full compass of notes, but it is as flat as the Borgia popes’ terra nostra. Mr. Dwyer stepped surely and vigorously into Hermann Keller’s effective and vigorous completion of the fragmentary Bach Fantasie in C, BWV 573. This concert movement, if you don’t yet have it in your ear, is a gem, and it is still fairly unknown to performers. In writing it, Bach appears to have glimpsed the same post-Corellian horizons as his cousin and contemporary, Joh. Gottfried Walther, not to mention gifted Unico Willem, Graf van Wassenær (author of a glorious set of concerti grossi). Each composer crafted a select body of worldly works radiant with Italian light, typically well suited for keyboard transcription. The Trio super Herr Jesu Christ, dich zu uns wend’,  BWV 655, and Schmücke dich, o liebe Seele, BWV 654, are two more Leipzig-Choräle. Some of the emotional power of the latter derives from an extraordinarily tight fabric enmeshing harmonic lines and the low-lying lead voice; one absolutely could not recast a single note. Mr. Dwyer’s pedestrian tempo in the first half of his closing Präludium & Fuga in C, BWV 547, ceded to a brisk lively engagement with the counterpoint of the fugue.

Gusts of brisk Piemonte air blew in with Torino organist Luca Massaglia, who provocatively re-registered familiar Bach — to an enthusiastic reception, let it be said. From its propulsive opening, the full-textured declamations of his kinetic “Dorian” Toccata & Fugue in d, BWV 538, seized the full attention of the numerous concertgoers. Why on earth is it that Italian organists (and cembalists) often impart such vocal freedom, within strikingly disciplined rhythmic bounds, to music that originated on the frosty side of the Alps? We continued to witness this in Mr. Massaglia’s masterful songfulness and emotional profundity in two Kirnberger-Choräle – Wer nur den lieben Gott läßt walten, BWV 690, and Wer nur den lieben Gott läßt walten, BWV 691. His ingenious, heartfelt registrations offered fresh looks at these old friends. His Herzlich tut mich verlangen, BWV 727, Liebster Jesu, wir sind hier, BWV 731, and the prayerful Vater unser im Himmelreich, BWV 737, were likewise invitations to peer into new and different sides of the Richards, Fowkes organ. As he began his last piece, Mr. Massaglia beckoned to an Italian imp, ed eccola!, we had a dramatically effective ripieno introduction to the entire rest of the titanic, BWV 533. Hearty and prolonged applause followed the end of this Fuga.

College of the Holy Cross senior Jacob Street played another of the large-scale non-liturgical works, the intense and challenging Prelude & Fugue in b, BWV 544, to begin his half-hour.  In offering the Trio Sonata No. 4 in e, BWV 528 (Adagio-Vivace; Andante; Un poco allegro), he explored every possibility of the quieter end of stop choices, though perhaps with less cantabile than one could have wished for. His In dir ist Freude, BWV 615 (Orgelbüchlein) was, alas, ineffectively fast. He activated the whirling small bells of the Zimbelstern, which increased the festive feel of the work.

James David Christie, long familiar to Boston audiences for his BSO roles now and again and for his presence as teacher and performer at Wellesley College, is among the most influential and prolific teachers on his instrument. Since taking on the punishing regular commute between Oberlin and Holy Cross, his most active posts in recent years, he has maintained the celebrated Chapel Artists Series at the latter at a high level. These concerts showcase the College’s important four-manual Taylor & Boody organ and a fine roster of the world’s best organists. Somehow, Mr. Christie also finds time for concertizing, organ and improvisation competition juries, and master classes on all the continents. Mr. Karosi was fortunate in securing him for the final recital of this splendid Bach celebration at First Lutheran. [Ed.: see review, “James David Christie in Bach Birthday Celebration.”] The earliest Bach music we have is the collection of around 38 Neumeister-Choräle whose discovery at Yale Christoph Wolff announced in 1985. Mr. Christie gave us four of these, and what a treat each of these youthful pieces is. Note the high Bach-Werke-Verzeichnis numbers! They show a certain delight at virtuosity, but always in the service of a powerful dramatic end. The big, declamatory Jesu, meine Freude, BWV 1105, and the more intimate Allein zu dir, Herr Jesu Christ, BWV 1100, were as attention-getting as they are unfamiliar. Further surprises came with Herzlich lieb hab ich dich, o Herr, BWV 1115, performed with the brightly present Zimbelstern, and the contemplative Wenn dich Unglück tut greifen an, BWV 1104, both of which illustrated the young Bach’s awareness of the compositional elements in his predecessors’ styles. Similarly, the 11 Partite diverse sopra Sei gegrüßet, Jesu gütig, BWV 768, was a kaleidoscope of registrational color and beautifully interrelated tempi. Prof. Christie has been heard to comment that the sometimes banal, always requested Toccata & Fugue in d, BWV 565, has appeared but a handful of times on his recitals over the decades. In his tempestuous interpretation at First Lutheran, with ornamentation and improvisational harmonic commentaries slipped into the time-worn folds of the piece, this was a gripping, one might say new score. Even if, as Mr. Christie’s notes for his Bach 325th Birthday concert (at Holy Cross, Worcester), held the following day said, “some musicians feel that BWV 565…may very well not have been written by Bach” and that it “is perhaps a transcription for organ of a lost violin work. …if it is not an original Bach work, I would still play it!

Veteran recording engineer Christopher Greenleaf collaborates with chamber, early, and keyboard musicians in natural acoustic venues on both sides of the Atlantic. He is active as a writer, translator, photographer, and acoustic consultant.