Two local women organists, as it happened, last weekend gave recitals back to back and Bach to Bach. The result was an object lesson in the difference between excellence and mediocrity.

The last in Memorial Church's noonday concert series, which was also the best, provided an opportunity to hear the consummate artistry of Lois Pardue, the Church's associate organist. She has been playing this large instrument for several years now, and she knows intimately all its virtues and shortcomings.

Although Mrs. Pardue's all-Bach program was a difficult one, she was in peak form and her playing was almost note-perfect. For once I did not have to worry whether the performer could just get through all the notes; I could assume this, and proceed to concentrate on other matters.

She brought to the music an impeccable stylistic taste in addition to technical virtuosity. Her admirable registrations allowed all the intricately woven lines of counter-point to come through clearly, with no frayed ends. Lois Pardue was never Lois perdue.

Especially notable was her command of rhythm and articulation. Neither mechanical nor distorted, her playing endowed every piece--fast or slow--with vitality; the music always lived, breathed, moved. And this is what is usually missing from Bach performances.

Her chief offering was the entire set of six Schubler Chorales, very rarely performed at one sitting. Written toward the end of Bach's life, they were transcriptions of six cantata movements (and one of only three sets of pieces to get into print during the composer's lifetime). All the same, they are, entrusted to the proper facile fingers and fleet feet, magnificently suited to the organ--Schweitzer notwithstanding.

Mrs. Pardue's performance of the opening chorale-prelude, "Wachet auf," was the first I have ever heard taken at a sufficiently fast tempo. With most players, it sounds more like taps than reveille. The only trouble was that the pedal stop had pipes that were rather slow-speaking; at this tempo, therefore, the bass line tended to lag perceptibly behind the upper ones.

The last two, "Ach bleib bei uns" and "Kommst du nun," are fiendishly hard. But Mrs. Pardue tossed them off as though they were elementary exercises.

She framed the chorale set with two unhackneyed examples of the favorite Baroque practice of juxtaposing a free and a strict form: the Fantasia and Fugue in C Minor and the Prelude and Fugue in B Minor. The latter fugue is a fine specimen of the many Bach fugues that are first-rate works wrought from an unpromising theme. Bach disproved the maxim, Ex nihilo nihil fit.

Mrs. Pardue's concert was, fortunately, well attended. There are few organists anywhere whom I listen to so willingly; and I hope Harvard realizes how lucky it is to have her services. "In dir ist Freude," Mrs. Pardue.

The next day a huge crowd turned up at Christ Church to hear its organist, Marion Boron, try to play Bach's Art of Fugue, or most of it. This performance was intended to illustrate her 1959 "discovery" of the symbolic intent behind this work, which she has described in a recently published monograph.

Miss Boron will be disappointed if she expects her addled theory to have the impact Hans David's did when he hit on a solution to the structure of Bach's Musical Offering. Her "dramatic exegesis" is so demonstrably absurd on dozens of grounds that there is no point in embarking on a full-scale refutation here (or anywhere).

"Would the world's greatest religious composer have spent his last days writing mere fugal exercises?" she asks. Her contention, briefly, is that The Art of Fugue "is Bach's story of the Crucifixion and Resurrection of Jesus and the salvation of mankind; including his own personal salvation in the final fugue. When he reached this point, the plan was too stupendous, even the master could not complete it." (No plan would have been too stupendous for Bach; but let's not go into that.)

Bach left us 19 pieces in this work, the last one incomplete. "The hidden key," Miss Boron says, "is in the number of four-part fugues." She claims Bach intended "these 14 fugues to correspond with the 14 Stations of the Cross," and blithely remarks that "the remaining fugues do not belong in the final version of The Art of Fugue."

To get her 14, however, she counts the upright and inverted versions of one of the 19 as two; and she includes one that is a three-part fugue! I wonder what her reaction will be if she ever learns that Bach planned to write a 20th piece--another four-voice fugue on four themes, which was then to be inverted note for note in all four parts.