Thomas Adès and the BSO chamber players. Photo by Robert Torres.

This year will, as everyone hopes, be the Boston Symphony Orchestra’s last season without a music director — at least for another five years. Andris Nelsons has been signed up, and although he’s conducting only two BSO subscription programs this entire year, he’ll be really and officially taking charge next fall. His photo is already on the cover of the BSO program book, with the title “Music Director Designate.” For his first Symphony Hall concert since he was appointed, the press was invited to a rehearsal and press conference, which the Boston Globe featured on the front page (unfortunately, having a day job, I couldn’t attend), and the concerts were the season’s first to be sold out. The Globe apparently wanted to give Jeremy Eichler a little more space than he gets for his usual overnight BSO reviews, so the most newsworthy review of the season didn’t actually appear until it turned up in the G-section a day later.  (Couldn’t the Globe make a little more room in the next day’s paper?)

Nelsons’s concerts (October 17-19) began with a static Siegfried Idyll. If Wagner intended this as a lullaby for his infant Siegfried, this would have been the perfect performance to put him to sleep. A quality that has disappointed me in a number of Nelson’s performances is that his slow movements have so little of the kind of phrasing that moves the music forward. Tension, along with the listener’s attention, droops. The strings sounded sumptuous. Nelsons arranged the instruments, unlike James Levine and most of this season’s other guest conductors, without separating the first and second violins antiphonally (the traditional 18th- and 19th-century seating place), but — like Erich Leinsdorf (if my memory hasn’t failed me) and unlike Seiji Ozawa — with the cellos opposite the violins and in front of the violas. This makes for a warm but more thickly textured string sound, so the impulse to lean forward into the flow of the music is all the more important.

Nelsons followed the Wagner with Mozart’s large scale Piano Concerto in C, No. 25, with the superb British pianist Paul Lewis making his Symphony Hall debut (he’d played Mozart’s 23rd Piano Concerto with Christoph von Dohnányi at Tanglewood in 2012 and gave a powerful Celebrity Series recital of Schubert’s last three sonatas earlier this year at Jordan Hall). But this time he was less effective, less urgent, less nuanced in his phrasing. This concerto is one of Mozart’s grandest and most outgoing, so if nuance goes, the very qualities that make this piece most interesting and compelling get lost. Lewis’s playing was fleet and glittering yet brittle, and once again, the conducting, however energetic, seemed rhythmically stiff-backed.

A few weeks ago, at the Discovery Ensemble’s first concert of the season, music director Courtney Lewis made the daring decision actually to begin the program with a Mozart Piano Concerto (the D minor, the one foreshadowing Don Giovanni, in a lightning-bolt performance, with young Israeli pianist Shai Wosner). I wish there had been something more daring to celebrate the incoming music director’s unique interests and qualities, even something a little less ordinary than the order of the pieces on the program.

Nelsons also had the odd habit of conducting with only his right hand, while frequently leaning against the guard rail with his left hand. Did the concussion that made him cancel last summer’s Verdi Requiem at Tanglewood make him afraid of losing his balance? I don’t remember seeing him do this before.

Andris Nelsons conducts the BSO. Photo: Marco Borggreve.

The significant success of this concert came after intermission: Brahms’s Third Symphony. Nelsons’s most successful Tanglewood performance in 2012 was his Brahms Second, but I thought this Third was better — the best live performance I’ve yet heard from him. This was not exactly a thoughtful interpretation — Nelsons doesn’t seem that kind of conductor — but here everything was working. The BSO brasses and winds were in top form (John Ferrillo’s tender oboe at the end of the second movement, James Somerville sounding that haunting horn call opening the third). The melancholy third movement dance — a kind of eerie tango — had that forward-leaning quality, that yearning, that tension between propulsion and reluctance missing in the previous pieces. This was the first time I’ve heard Nelsons in person that he seemed to be really inside the music. And the warm standing ovation he received for the Brahms matched the standing ovation welcoming him at the beginning of the concert, only this time it was not just for something he was but for something he had actually accomplished.

The most controversial concert of the BSO season turned out to be the first. After a gala, Pops-style opening night, the BSO returned to serious business with Mahler’s Symphony No. 2 conducted by the venerable and now frequent guest conductor Christoph von Dohnányi, whose approach was to almost italicize the way Mahler shoehorned the contrasting pieces of this gigantic autobiographical puzzle into a single work. I liked it, especially the sardonic Scherzo, which orchestrates without including the words to Mahler’s satirical song about St. Anthony’s preaching to the fishes (they listen seriously then completely ignore the sermon), with Dohnányi characterizing the variety of fishy responses. Full-voiced British mezzo-soprano Sarah Connolly sang the famous “Urlicht” (“Primal Light”) with honest, unshowy earnestness. In the smaller vocal role, Swedish soprano Camilla Tilling chirped prettily, though with a bit of an edge and less affect (my discerning friends thought she was better than that). The Tanglewood Festival Chorus, singing the 18th-century German poet Friedrich Gottlieb Klopstock’s poem “Resurrection” (which gives this symphony its nickname) from memory, nearly stole the show with its warmth, accuracy, and passion.

By far the best concert of the fall season was the one led by composer Thomas Adès, his third visit to the BSO as guest conductor. No one’s programs since the departure of James Levine have been more thoughtful or surprising — or narratively coherent. In 2011, for example, he led excerpts from his own opera and works by other composers all based on Shakespeare’s The Tempest. This time the program was mainly about voyaging. First to the Hebrides Islands off the coast of Scotland in an exhilarating performance of Mendelssohn’s inspired “Fingal’s Cave” Overture. Then around New England, in a spectacular performance (the BSO’s first) of Charles Ives’s Orchestra Set No. 2, with its multiple layerings of personal and cultural memories: what Ives biographer Jan Swafford calls the “time-suspending,” “dreamlike,” and “mesmerizing” “An Elegy for Our Forefathers;” then the “virtually cubist” evocations of both hymns and ragtime in “The Rockstrewn Hills Join in the People’s Outdoor Meeting;” and ending with the achingly complex response to the sinking of the Lusitania in “From Hanover Square North, at the End of a Tragic Day, the Voice of the People Again Arose.” Adès’s own “Polaris,” Voyage for Orchestra (2010), took us into outer space. Gorgeous, yet tonally more conservative than the Ives, with its exotic array of marimba, vibraphone, glockenspiel, bells and chimes, piano and celesta, and two harps, in which musical themes whirl out from a mysterious center and five small brass ensembles in both balconies add to the expanding spaciousness and consciousness.

I attended the opening Thursday night concert (October 10). At the Friday evening “UnderScore” concert, the Adès was accompanied by a screening of Israeli-born video artist Tal Rosner’s projection of images of seashore, human figures, and abstract animation. The YouTube clip didn’t make me sorry to miss it, especially since the abbreviated Friday concert left out Adès’s conducting an intense, revelatory version of the familiar César Frank D minor Symphony — mysterious, slashing, emphasizing contrasts in textures, giving fresh life to connecting passages overlooked by most conductors, and featuring Robert Sheena’s memorable English horn solo in the slow movement. In an angry letter to the Globe, a BSO patron complained about being short-changed by the Friday program.

On Sunday, the BSO Chamber Players celebrated the beginning of their 50th season, with the multi-threat Adès playing harpsichord in his early “Sonata da caccia” (1993) inspired by Couperin and Debussy, with oboe (John Ferrillo) and horn (James Sommerville) — the instruments for a chamber piece Debussy never lived to complete. Adès closed the program playing piano in his later (2000) Quintet, with violinists Haldan Martinson and Elita Kang, violist Mark Berger, and principal cellist Jules Eskin. He was also the superb pianist for Ravel’s Chansons madécasses (“Madagascan Songs”), in the afternoon’s most stunning performance, with Eskin, flutist Elizabeth Rowe, and a most impressive young baritone named John Brancy (in what is usually a woman’s role) singing Ravel’s three songs, the middle one startlingly interrupting the languorous sexuality with a violent outcry against imperialism.

Except for Adès, the playing was uneven. Rowe, violist Cathy Basrak, and harpist Jessica Zhou gave a skillful rendition of Debussy’s late Sonata for Flute, Viola, and Harp, but left out all the insinuation, the perfume that brings this unusual piece to sensual life. Adès’s own pieces probably needed more rehearsal. About halfway through the single movement of the sonically complex Quintet he actually started conducting from the keyboard.

An earlier BSO guest conductor, Stéphane Denève (October 3-8), once paired with Nelsons as a possible BSO music director, led the first BSO performance of Prokofiev’s complete orchestral suite from his opera Love for Three Oranges since Serge Koussevitzky played the American premiere with the BSO in 1926 (its familiar March has been repeated numerous times). Cheeky and languid, it got a dazzlingly exhibitionistic performance, and the Shostakovich First Cello Concerto had Yo-Yo Ma contributing his deep humanity. Denève ended with a competent but uninspired Strauss Ein Heldenleben (which the BSO program translated as “A Heroic Life” rather than the more familiar “A Hero’s Life”) — Strauss’s extended piece of self-promotion that needs all the inspiration it can get. Concertmaster Malcolm Lowe received an especially warm reception for his big violin solo depicting Strauss’s wife Pauline, his first major solo since returning to Symphony Hall after rotator cuff surgery.

And last week (October 24), British conductor Daniel Harding, a former Tanglewood conducting fellow and disciple of Simon Rattle, made his BSO debut leading the BSO debut of British composer Marc-Anthony Turnage’s Speranza, a BSO co-commission (Turnage is best known as the composer of the mod opera Anna Nicole, which was the last production, a popular and critical hit, of the now sadly defunct New York City Opera). A small audience welcomed the composer, but the piece in three elephantine slow movements interrupted by a livelier third movement sounded, on a first hearing, too much like heavy-handed 1940s movie music. The inclusion of the duduk, a plaintive Armenian wind instrument, and cimbalom, a Hungarian hammered dulcimer, added unusual coloration. Turnage apparently dropped an entire movement after this year’s London premiere (also led by Harding), but he probably should drop at least one of the slow movements as well.

The concert concluded with a bewilderingly flat attempt at Mahler’s sublime Song of the Earth, in which none of the parts seemed to add up. The singers were tight (almost strangulated) German-Canadian tenor Michael Schade (a particular victim of Harding’s inability to keep the orchestral volume down) and Dutch alto Christianne Stotijn, whose pleasant voice has too much spread and who had to resort to chest register for low notes.

Besides the BSO were some other strong orchestral concerts. At Emmanuel Music (September 28), director Ryan Turner led a strong and convincing performance of an irresistable piece that isn’t played often enough, Beethoven’s Triple Concerto, with violinists Heather Braun, cellist Rafael Popper-Keizer, and — especially — pianist Robert Levin making the solo parts not only sound like real chamber music but also sing. Some rarely-heard vocal ensembles preceded the Triple Concerto, but the performances lacked a necessary insouciance and charm.

Benjamin Zander and the Boston Philharmonic returned to Beethoven’s Ninth Symphony for the first time in nearly two decades (a concert postponed from the Boston shutdown after the Marathon bombing). Zander has for many years been concerned — even obsessed — with Beethoven’s controversial metronome markings, which many musicians feel are unrealistically fast. But coming very close to those markings, yet somehow not focusing on them, this Ninth (I attended the last of three performances) had a fleet transparency that was immediately infectious, gripping, and finally quite moving. The orchestra and the Chorus Pro Musica were both superb and polished. The proto-Mahlerian awakening had an edge-of-the-seat suspensefulness. The second movement gallop was an exciting juggernaut. The third movement Adagio (“cantabile”) was like a floating — indeed, sailing — lullaby, with a single, unstoppable pulse. Beloved Boston baritone Robert Honeysucker was outstanding among the four vocal soloists for both the size of his voice and his power of declamation (it’s he who announces the switch in tone to the Ode to Joy). Soprano Michelle Johnson hit a solid climactic B-flat. Tenor Yegishe Manucharyan seemed to have the wrong voice for this heroic part. And I couldn’t hear mezzo-soprano Sarah Heltzel at all.

The evening began with Beethoven’s Coriolan Overture. Zander made the most of its dramatic pauses and wholehearted emotion. High praise to say that the Ninth Symphony lived up to this masterful prelude.

And to return to the Discovery Ensemble, Courtney Lewis’s accomplished young players stood out not only in the Mozart concerto, but in the mesmerizing Ligeti Melodien (“Melodies”), with its uncanny, unearthly textures, through which snippets of melody kept trying to break through. The program ended with a rich-sounding performance of Sibelius’s oddest symphony, his Sixth, with its numerous anti-climaxes. It was as if Lewis were still in the sound world of Ligeti, in which accompanying rhythmic figures were continuing to suppress the pastoral tunes attempting to reach the surface. Finally, this got a little frustrating, and I couldn’t erase my memories of Thomas Adès’s version with the BSO last year in which the tense balance between tune and texture was more completely realized.