For Thursday’s ambitious program, Dudamel demonstrated that a really big band (160-plus) could float like a butterfly and sting like a bee (at least one definition of “the greatest” I accept) — and also penetrate deeply into deeply penetrating symphonic thought. This was a spectacular, stirring and flashy show. Friday’s program was even flashier. Dudamel began with Beethoven’s Fifth Symphony.

The orchestra was large, far larger than is fashionable in these historically informed days, but not humongous. There were certainly plenty of basses to dig in ferociously. Dudamel, who conducted everything without scores both evenings, inhabited the orchestra. A wild enthusiastic swoop of his arms elicited a wild enthusiastic swoop of strings. This was bold big Beethoven, but the playing was much too joyously alive to be old-fashioned big Beethoven.

Care must be taken not to condescend to these kids. Some are as young as 12, although most look to be in their early 20s (26 is the cutoff age). They are not great young musicians, they are world-class players, period. They provide uniquely visceral thrills as an ensemble. But in two evenings, I also heard more wonderfully expressive oboe, flute, clarinet, bassoon, violin, horn and trumpet solos than I could count.

The second half of the evening, devoted to Latin American music, was when the audience began, understandably, to lose it. The orchestra swelled to what must have been close to 200. Jos Pablo Moncayo’s Mexican classic “Huapango” and the more recent and just as lively and populist “Danzon No. 2″ by the contemporary Mexican composer Arturo M rquez, were dazzling in their rhythmic vitality and flirtatious dynamics.