CELLIST DIAZ AT AMBASSADOR

Like all the performers on the Gold Medal series at Ambassador Auditorium, Andres Diaz is a contest champion. At 22, the cellist is younger than most, however, which seemed both help and hindrance Monday evening.

Diaz stormed passionately through the tempestuous parts of Schumann’s Adagio and Allegro and Brahms’ Sonata in F. The simplicity of the more reflective moments sounded heartfelt, and the whole emotionally urgent and musically sweeping.

But at times his impetuosity produced an almost incoherent babble of unfocused sound. Diaz apparently favors the explosive slap of stick against string when digging in, which, coupled with loud foot-tapping, reduced some passages to pure percussion.

The breathless sense of adventure was worth the sonic annoyances, however. Diaz also had the benefit of the controlled, well-integrated playing of pianist Heng-Jin Park, a fellow graduate student at the New England Conservatory.

In the second half, the Chilean-American cellist shed his tendency to overplay. His tone sounded freer, and he seemed totally captured by the subdued intimacies of the muted “Nana” and “Asturiana” transcribed from Falla’s “Siete Canciones.” Ironically, it was the reliable Park who turned to obtrusive foot-tapping in the “Polo” and “Jota.”

If Diaz’s playing was more controlled, he lost none of his intensity. Gunther Schuller’s Fantasy for solo cello is a big, dramatic, craggy, complex exhibition. Diaz ignited it with coolly calculated, yet thoroughly committed bravura, and a nice feeling for musical shape.

After all this, Luigi Silva’s Variations on Paganini’s 24th Caprice proved something of a letdown, in dazzle as well as substance. There was no encore.