Thursday’s Seattle Symphony concert at Benaroya Hall featured two young musicians who are reaching the rarified atmosphere of fulfilled promise in their careers. Of the two, cellist Gautier Capuçon and conductor David Afkham, Afkham is the rarer bird. Conductors usually reach musical maturity later than instrumental musicians, and Afkham is only 29.

An orchestra is a very tricky instrument to “play.” Conductors’ knowledge of each instrument’s capacities and constraints, the encyclopedic knowledge of a myriad scores, as well as a composer’s intent, and the musical style of a composer’s era, are all essential to a conductor’s understanding even before he or she hones the ability to impart that knowledge and insight to an orchestra of maybe a hundred musicians who often feel they know better what’s required than the conductor does.

German-born and educated, Afkham finished his conducting studies at age 24 and the following year won the Donatella Flick Conducting Competition, which earned him the position for a year of assistant conductor of the London Symphony Orchestra and its conductor Valery Gergiev. Impressively, he has since conducted, and been rehired for more concerts, by the Cleveland Orchestra, the Amsterdam Concertgebouw and the Deutsches Symphonie-Orchester Berlin among others, none of them orchestras who would consider accepting anyone second rate.

For Thursday’s concert, Afkham conducted Britten’s Cello Symphony, bracketing this less-known work with Mozart’s Overture to Don Giovanni and Beethoven’s Symphony No. 5.

French cellist Capuçon, 31, has also made a name for himself, particularly in chamber music with many well-known names. Of his performance of the Cello Symphony here, most arresting from the start was his tone. He plays a Goffriller instrument from 1701, and from it he drew a sound that was bright but never brash, mellow, velvety, glorious, and strong as well as able to whisper, all aspects which he needed in the Britten.

This work with its symphonic structure is not a concerto per se, but it is concerto-like in its showcasing of one instrument. It’s not a comfortable piece of music, but it’s also not spiky or violent, more one which has you hopping to keep up with the changes and ideas Britten brings.

The harmony is often spare with upper or lower strings remaining silent for extended periods and considerable use of the brass and woodwinds. Britten makes sure the cello, which plays most of the time, can always be heard against contrasting ranges in the other instruments and frequent soft pizzicato from the strings. Capuçon spent much time high on his top string, making sounds which might come from a violin but with more depth and sonority given the resonance of the instrument. At others he was on his lowest strings, creating the same warm depth and resonance, so that every note he played sang.

There’s nothing hummable about the Cello Symphony, nor is it a work to feel familiar with at first hearing, but in Afkham’s and Capuçon’s hands it was continually stimulating and arresting to hear.

The Mozart which began the concert with a small orchestra, showed Afkham as a decisive, often dynamic conductor, but it was his conducting of the Beethoven which was electrifying.

He took this very familiar work at what is now thought to be the speed intended by Beethoven, much faster than it has generally been played in the last century. The performance was vivid from the eerie start on, rushing forward, repeating, full of dynamic contrasts and tension interspersed with lyrical moments, never shrill or forced. The gentleness of the second movement seemed amazingly relaxed in contrast to what had gone before, and the last two movements with their look back to the beginning, and building from carefree and cheerful, to exciting, to joyful and triumphant left the listener almost breathless. Definitely a conductor to watch, and to bring back.

There are two more performances, tonight and Saturday, March 23.