The final 45 minutes of yuletide rock enigma Trans-Siberian Orchestra's set Friday at the Wells Fargo Center was packed with the over-the-top, guitar-solo-laden Christmas jams that attract the group's rabid fans by the thousands. It nearly made up for the first 100 minutes.

The seven-member band - two guitarists, two keyboardists, a bassist, a drummer, and one very energetic violinist - played effortlessly with nine backing singers, a seven-member string section of local players, plus a light and pyrotechnics show right out of Apocalypse Now.

Trans-Siberian Orchestra's songs, which repackage familiar classical music themes and tease them out with hair-metal pantomime and arena-rock bombast, have proved such a winning formula that the TSO franchise dispatches two separate touring units each holiday season.

TSO East, the troupe that played in South Philadelphia, was mind-blowing in the final section of the show. The players riffed righteously on the Beethoven-cribbing "Requiem (the Fifth)" as columns of fire erupted behind them, blasted through the Nutcracker-nodding "A Mad Russian's Christmas" while the guitarists perched and preened on telescoping platforms that arced high above the crowd, and closed triumphantly with "Christmas Eve/Sarajevo 12/24" and its crowd-pleasing take on "Carol of the Bells."

In the show's underwhelming first half, TSO performed for the first time the final installment of its Christmas trilogy of rock operas, The Lost Christmas Eve.

The songs were no less extravagant nor outlandishly Christmasy - particularly "Wizards in Winter" and "Christmas Jam," in which guitarist Chris Caffery and violinist Roddy Chong sprinted through the crowd to played atop telescoping trusses at the back of the arena.

The problem was the pieces were performed between mind-numbing stretches of cloying exposition by narrator Bryan Hicks, who used artlessly blunt rhymes and tortured syntax to relate the opera's morally murky, credulity-straining plot: An angel on a one-night mission from God to find a human who embodies his son's values sets an emotionally crippled businessman (natch) on a path that leads to his reconciling with the mentally disabled son he'd selfishly abandoned years earlier. As though forgiveness and redemption are ever that easy.

Overall, the spectacle was as confounding as it was enthralling, a perfectly orchestrated testament to the excess that defines Christmas in America.