No need to wish Yannick Nézet-Séguin the best of luck.

The Philadelphia Orchestra's music director-designate has arrived this week in his future home - with his likeness on Kimmel Center banners, an I-95 billboard, and Center City bus shelters - on the heels of a loudly applauded Berlin Philharmonic Orchestra debut and anticipating a return to the Metropolitan Opera in Verdi's Don Carlo in December.

As fun and easy as 35-year-old Nézet-Séguin makes everything look, his debut at the fabled Berlin orchestra - the apex of his career so far - was hardly putty in his hands, and now the pressure is on for his Friday-through-Sunday Philadelphia Orchestra concerts, the first since his appointment was announced in June.

Between rehearsals are extensive media interviews, a celebratory breakfast with orchestra members, and post-performance meet-and-greets with the audiences. Many conductors shrink from such extramusical activities. Not him: "I love making music with others, so I love to be surrounded by people."

Nézet-Séguin (pronounced Yah-NEEK Neh-ZAY Say-GUN) also understands how important such appearances are at this time.

"It's a very special moment . . . when an orchestra and community get a new chief conductor," he says of the job he'll assume in 2012. "I don't want to walk on eggshells or enter through the back door. It's good for the orchestra to make the most out of it."

That's particularly the case in the orchestra's current financially fragile state - of which he's well aware. "My responsibility . . . is to focus everybody's energy in the same direction," he said. "I'm not here to make a revolution. I'm here to keep a tradition, but also to widen the perspective."

The orchestra's search for a new music director began in earnest in 2006, when then-maestro Christoph Eschenbach and the orchestra announced they would part ways after the 2007-08 season.

With few deep relationships to fall back on, and amid spiraling financial difficulties - deficits, falling ticket sales, eroding endowment and donations - the orchestra looked for someone willing, able, and likely to boost its image. After only two dates, rising star Nézet-Séguin signed on, adding Philadelphia to his current posts with Montreal's Orchestre Métropolitain, the Rotterdam Philharmonic Orchestra, and the London Philharmonic Orchestra, where he is principal guest conductor.

His effervescent manner has quickly won over audiences in Philadelphia and nearly everywhere else. After conducting Berlioz's Symphonie Fantastique with the Berliners, he was called back for more bows even after the players had left the stage.

Critics and orchestra musicians can be suspicious, especially in a music-rich community like Berlin's. Yet it was a typical debut in the young Montrealer's career. Reviews had a wait-and-see tone - with bursts of enthusiasm - and orchestra insiders say a next-season reengagement in this tough musical market is all but assured.

"This little whirlwind has what it takes," critic Clemens Goldberg, on RBB Kulturradio, said of the 5-foot-5 conductor.

"Afterwards, we saw one of the musicians backstage and asked how it went. He said 'We had a good time,' " said Richard Worley, chairman of the Philadelphia Orchestra board, who was there for one of last week's performances. "I thought it was a joyous occasion."

Here, Nézet-Séguin faces the ultimate follow-up with Philadelphia Orchestra concerts that require a full range of conducting technique: Haydn's buoyant Symphony No. 100 (1794) and Mahler's gargantuan Symphony No. 5 (1902). It's also good box office: Tickets are available but not plentiful, especially for Friday's opening concert.

"This program was designed - before I was appointed - to be a completion of an overview of what I can do in certain repertoire," he said.

Of the Mahler, he said, "I think that one of my strengths is this postromantic German repertoire - which is one of the strengths of the orchestra. . . . So it's not like I'm bringing a novelty. However, I believe my approach will be sufficiently different."

How different? Unlike the work of many current conductors, Nézet-Séguin's version of the famous "Adagietto" (used in films such as Death in Venice) doesn't linger, according to violinist Davyd Booth, even though he often asked for "gravitas."

"There's something very natural about his feeling for the pacing," Booth said. "The [Wednesday morning] rehearsal went fabulously well."

"They know what I want. I know what they do," Nézet-Séguin said of the rehearsal. "That's not to say we've arrived - there's a lot to be developed. But I feel like I'm already home here."

His remarkably consistent way of building such musical relationships was apparent as he started from square one in Berlin. Though he makes a point of working with an orchestra's fundamental qualities, Nézet-Séguin isn't afraid to take ensembles out of their comfort zone - even the Berliners, who were characterized by current principal conductor Simon Rattle as sometimes not agreeing with him on anything.

Upon meeting resistance, Nézet-Séguin clarified his thoughts to the musicians and always asked twice - while believing they had only the highest of motives.

"These are individuals who really care about what they're doing. They want to believe in it and put their full heart into it. Otherwise it would be false because they're just doing it because the conductor asked for it," he said.

The musicians felt the distinctiveness of his approach. "I played the piece under Herbert von Karajan [the orchestra's legendary principal conductor from 1955 to 1989] . . . and he had a more bombastic approach and a seamless line. The way we're doing it tonight, more of the bones . . . of the symphony are coming out," said the Berlin's longtime hornist, Stefan de Leval Jezierski, before last Thursday night's performance.

Steel nerves aren't necessarily the key. Many artists galvanize themselves with mental shell games. This is Nézet-Séguin's version:

"I don't want to show up on the podium like this little kid who is afraid. I've never really been that way," he said. "I want to treat this Berlin Philharmonic debut like just another day at the office.

"Of course it's not. But in many ways, it is - making music with great musicians."

And this week, in Verizon Hall.

If You Go

The orchestra performs

8 p.m. Friday and Saturday, 2 p.m. Sunday at Verizon Hall, Broad and Spruce Streets. Tickets: $43-$147. 215-893-1999 or www.philorch.org.EndText

Contact David Patrick Stearns at dstearns@phillynews.com.