With exceptional solo work by several Pittsburgh Symphony Orchestra principals, a performance Thursday night was less a concert than a talent show.

The PSO's chamber orchestra took the stage at Carnegie Music Hall with a varied program that showcased some singular talents in the group, beginning with clarinetist Michael Rusinek.

With flutist Damian Bursill-Hall having broken his pinky in an accident at his home earlier in the week, a scheduled piece by John Corigliano was replaced by Heinrich Baermann's Adagio for Clarinet and Strings. A once-renowned clarinetist, Baermann's work was essentially a showpiece for Rusinek, who took the ravishing, patient melodic line to exquisite heights. Judges would have been tempted to pull out the 10 right there.

Bassist Jeffrey Turner "sat in" with the group in a jazz-infused premiere by Leonardo Balada. The Carnegie Mellon University composer's "Caprichos No. 4," is scored for double bass, chamber strings and clarinet, but what's interesting is the program -- a series of vignettes based on various jazz idioms. Like Copland's Clarinet Concerto, Balada approximated jazz, from the cool heat of bebop to a soulful meditation on spirituals to a re-creation of a New Orleans street funeral to a dance swing.

Turner's smooth tone and agility rendered the double bass something closer to a cello or violin. But Balada used him more effectively in the inner movements than the outer ones. Turner sounded like an instrumental Paul Robeson in the second, and he delicately intoned harmonics in the dirge-like second. While these movements had inner balance, the outer two never quite captured the vivaciousness of a combo or a swing band, in part because Turner was occasionally overpowered by the orchestra, conducted by Cardenes.

PSO trumpet player Charles Lirette's talent? Nothing less than playing the trumpet while smiling. His soloing in Albinoni's Trumpet Concerto in B-Flat, "San Marco," was a joy to watch as much as to hear. Lirette was just having a good time, especially coordinating the piece with Cardenes who led from the first chair. Playing a piccolo trumpet, Lirette displayed a golden tone, a lyrical line and a penchant for playing to the end of even fast notes. The result made the hall seem more reverberant than it is. With short bow strokes and light phrasing, the orchestra musicians provided the appropriate support in this Baroque gem. The fact that they earlier performed a movement from Corigliano's Symphony No. 2 -- a brilliant, driving Scherzo -- displayed their skills, too.

In hindsight, it would have been best to have left this Scherzo or the Behrman off the program because it was too long and left some of the audience, including myself, fatigued for the most substantive work of the night: Brahms' "Sextet No. 1." From the noble timbre of opening gesture to the frenzied finale of this work (Brahms clearly wanted the musicians to get a workout), it was clear once again that orchestra musicians are best for larger chamber pieces. I will take their ability to listen, blend and be subordinate when necessary any day for sextets and octets and the like, rather than combining two quartets. The players here -- violinists Cardenes and Jennifer Ross, violists Tatjana Mead Chamis and Marylene Gingras-Roy, and cellists Anne Martindale Williams and Michael Lipman -- lent the work the orchestral quality Brahms sought.

The program repeats at 8 tonight at Upper St. Clair High School.