If you've never had the odd pleasure of hearing the musical term "Mannheim Rocket" explained by a man in a poison-green suit and silver-glitter loafers, you probably missed one of the more interesting moments in the Philadelphia Orchestra's all-Mozart weekend.

The run of concerts trotted out three overtures, three piano concertos, and three symphonies Thursday, Friday, and Saturday.

Saturday morning brought the bonus of a 45-minute family concert hosted by the man in green, Dan Zanes, who recommended a large spoon as the conducting implement of choice to a delighted Yannick Nézet-Séguin.

Perhaps unintentionally, that concert acted as a midterm on the ensemble-music director relationship. The overture to Così fan tutte opened the mini-fest Thursday in tumble-forth mania, gasping for air. It was unchanged at Friday's matinee. But amid Saturday morning's informality, it settled into a more relaxed, yet still peppy, groove. Other works also gained confidence.

The promising news is that even given the rehearsing challenge of four different programs in five concerts, the bare minimum level of authority the orchestra exhibits with its music director is pretty high. Saturday night's Symphony No. 41 and Thursday's No. 39 only suggested genuine interpretive thinking. But Friday night's darker repertoire revealed something more than an incipient partnership. You might not have liked removing the G minor Symphony No. 40 from the 20th-century view that, despite its 18th-century pen date, it belongs to the 19th. Slimming down the vibrato, not to mention halving the string corps itself, made it a lithe, even ghostly, being. But it was from start to finish a complete vision of the work.

Not so the D minor Piano Concerto No. 20 on the same night. Nézet-Séguin stuck to his quasi-period view, but pianist Jan Lisiecki, in the most trenchant moment of his five-concert run, was already in Beethoven's world, not only in the cadenzas written by Beethoven, but throughout, in terms of his scale of sound and emotion. In his residency, Lisiecki was mostly beautiful and straitlaced; in the D Minor, he was beautifully dangerous.

By assembling varied views of Mozart, Nézet-Séguin was stating the obvious. Was this an artistic project or a marketing venture? By disrupting convention and changing programming, the orchestra encouraged repeat visits.

But real artistic exploration? There are 30 other Mozart symphonies no one really knows. Zanes had the metaphor right. A little spoon-feeding of novel repertoire would have gone down mighty easy.