The Tanglewood Music Center Orchestra, consisting of roughly 110 players from East Asia, Australia, Europe, and the whole United States, met for the first time a little over a week ago. On Monday night in the Koussevitzky Shed, musicians who had largely been strangers to one another beforehand, debuted as an ensemble. This annual event at Tanglewood repeated this year for the 75^th time. During my years on the staff of the Boston Symphony in the 1980s and ‘90s, this opening concert was referred to as the “annual miracle,” given the musicality, enthusiasm, and extraordinary ensemble apparent at the TMCO’s first outing.

That description is still worth hanging onto, not as a marketing device, but simply as an expression of wonder. Monday night the two conducting fellows (for the first time this year they are both women, which might have aroused astonishment a generation ago, but now is simply a fact) each led one piece in the first half of the program, while Stefan Asbury, himself a conducting fellow in 1990, a member of the faculty since 1995, and now coordinator of the conducting program, led the entire second half.

Asbury explained to the audience (or at least those who might not know) the nature of the orchestra and the program. To give the audience a chance to appreciate the individual musical quality of as many of the performers as possible, he said, the first half would consist of two important variation sets, each of which offered many solo opportunities.

The first of these was Britten’s Young Person’s Guide to the Orchestra, the title that was given here in preference to its more formal alternative, Variations and Fugue on a Theme of Henry Purcell, because of the presence of a narrator—in the person of choreographer Mark Morris—to read the original script introducing the instruments in the documentary film for which Britten composed the score. It was a charming idea, though the narration is sometime almost unbearably coy (the flutes are “a superior form of penny-whistle”) or minimally informative (“I expect you all know the sound of the trumpet”). In addition to this, Morris got rather arch himself when he changed the script to say that the harp has 47,000 strings (instead of 47) and 700 pedals (instead of 7).

Still, the performance, conducted by Ruth Reinhardt of Saarbrücken, Germany, currently studying at Juilliard, was well paced, with clear gestures and focus on the essential performers in each section, shaping the color and the wit of Britten’s clever score to its busy climax with the brasses pouring out Purcell’s theme in a broad cantilena while everyone else is making a glorious noise with Britten’s lickety-split fugue.

The second work on the program was the locus classicus of orchestral variations, the set that Brahms composed on a tune presumed to be by Haydn. For this Marzena Diakun, who has studied in Wrocław, Poland, and in Vienna, shaped each of the variations clearly and directed Brahms’s sometimes tricky rhythmic counterpoints with a distinctive contrasting beat in each hand. It is a matter of taste, but I felt that sometimes the breaks between variations were longer than ideal, but by the time of the passacaglia that builds to its climax, the momentum was firm and the breaking out of the original theme at the top of the orchestral texture a joyous event.

A significant novelty opened the second half: a work composed by John Williams as a gift to the Tanglewood Music Center and the orchestra on this 75^th anniversary. It is a short, vibrant, busy orchestral score—calling it a “scherzo” would not be amiss—with a title invented as a counterpart to the old joke: “How can I get to Carnegie Hall?” “Practice, practice, practice!” In the new piece the question seems to be, “How can I get to Tanglewood from downtown Lenox?” and the answer is, “Just Down West Street—on the left.”

In his own note Williams wrote of “…this little piece from which, I hope, the players of the TMC Orchestra might derive some small pleasure.” That pleasure certainly involves the lively interplay of tricky fanfares, busy 16^th-note figures in the strings, later elements added by woodwinds against strings, building to a sonorous climax leading to a gulp-inducing sudden ending. It is a virtuoso showpiece that kept Stefan Asbury and the players busy and intent to enthusiastic purpose.

The major symphony of the concert was the Sibelius Fifth, a work that intertwines busy repeated figures that appear as small motives and grow into larger structures, often hushed and barely at the level of perception, but then building to massive climaxes. Like the variation sets in the first half, Sibelius put the players through their paces in a pretty athletic way, which in itself seemed like a link to the Williams piece.

All in all, an exciting first outing for a “new” orchestra that survives but a single summer, and then disperses on the musical winds to the rest of the world.

Steven Ledbetter is a freelance writer and lecturer on music. He got his BA from Pomona College and PhD from NYU in Musicology. He taught at Dartmouth College in the 1970s, then became program annotator at the Boston Symphony Orchestra from 1979 to 1997.