From one moment to the next, The Seasons — the oratorio by Haydn, not the concertos by Vivaldi — felt in a Thursday concert at the Kimmel Center like a lost continent of music, but with all of the comforts of home.

Only now has the four-part, two-hour-plus oratorio had its first complete Philadelphia Orchestra performance (the 1994 outing was cut). Too big to be forgotten but easily bypassed in favor of Haydn's more popular oratorio The Creation,  The Seasons, finished in 1801, is the summation of the composer's 50-year-plus career. Even knowing that, I hadn't heard it in years following an authentic-instrument performance where the horn section had repeated train wrecks.

With his interest in Haydn masses, music director Yannick Nézet-Séguin made a natural segue into The Seasons with a great lineup of soloists — soprano Regula Mühlemann, tenor Werner Güra, and bass Matthew Rose — that promised to be a highlight of the season. That didn't quite happen on Thursday. Particularly in the first half, you sensed that everybody had solidly learned the piece but hadn't determined how to make it all it could be, particularly with a fundamentally twee text's picturesque portrayals of hardworking men and virtuous women in all kinds of weather.

The choruses outdo Handel with their mastery, wit, and invention. The word-painting effects are more subtle and distilled than in The Creation. At times, Haydn juggles the trio of soloists, chorus, and orchestra with youthful audacity and the resourcefulness of a veteran. (Remember, he wrote 15 operas). The Achilles' heel here is characterization: Though Haydn vividly projects states of being, there's none of the psychology that Mozart's operas and Bach's passions lead us to expect, which limits the depth of experience the piece has to offer.

Of course, the music is deeply appealing, and there's lots of it. The many lyrical oboe solos kept the orchestra's Richard Woodhams unusually busy. Davyd Booth's harpsichord playing was as restlessly colorful as the music itself. But as in Haydn's operas, vocal casting is mildly problematic: Mid-weight lyrical voices are in order until there's an unexpected flight of coloratura, and singers can't always do both.

That said, the vocal trio was nearly ideal, just a bit green. Soprano Mühlemann is a young European singer who normally wouldn't make her way to Philadelphia for years; the voice is a marvel for its clean technique and spring-water clarity. Tenor Güra is one of the finest art-song interpreters of our time, and you knew that from the way he molded the music for maximum impact, especially the recitatives. And Rose, the bass, is an old friend from his Curtis Institute years; his big voice never booms. His beauty of tone grows entirely out of what shade of expression he is going for.

The Philadelphia Symphonic Choir connected well with the fugal sections, but so often the sound lost its focus, especially at lower volumes.

Nézet-Séguin's cogent brand of electricity didn't arrive until after intermission; the orchestra had been rearranged with percussion off to the sides, and the players needed time to settle in. But in the finale — which can fizzle because it involves an apotheosis that I don't think the composer quite believed himself — Nézet-Séguin willed the music into being more than it is. Oh, by the way, the horns did just fine.

"The Seasons" is repeated at 8 p.m. Saturday at the Kimmel Center. Tickets: $39-$158. Information: 215-893-1999 or www.philorch.org.