The Guarneri String Quartet may have done its farewell tour thing a couple of years ago, but it has stayed on in its longtime role as quartet-in-residence at the University of Maryland, where, from time to time, in the company of other U-Md. musicians, the players resurface in the guise of “Guarneri and Friends.” On Friday at the Smith Center’s Dekelboum Concert Hall, this, too, came to an end with “Guarneri and Friends — The Final Concert.” It was a bittersweet occasion: Old friends engaged in their familiar undertaking but without the intensity or emotional power that had made their earlier collaborations so musically satisfying.

As a last piece, they chose the first of the Brahms String Sextets, a warmly orchestral-sounding work whose rhythmic and harmonic structures require an enormous sense of breadth and momentum in its performance. Unhappily, momentum, particularly in the second movement, got lost in attention to detail, and without momentum, breadth morphed into plodding. Cellist Evelyn El­sing and violist Katherine Murdock, U-Md. faculty members, joined the Guarneri four and melted comfortably into the ensemble, although Murdock had a real challenge on her hands in trying to match the power and warmth of Michael Tree’s viola tone.

The concert opened with a gently transparent reading of Beethoven’s Variations for Piano Trio in E-flat, Op. 44, which, despite its opus number, is a youthful effort and very much anchored in formulaic classicism. Pianist Rita Sloan joined violinist John Dalley and cellist Peter Wiley here and, wisely, the three kept things uncomplicated and straightforward.

Mezzo-soprano Delores Ziegler joined Sloan and the quartet for Chausson’s “Chanson Perpetuelle.” It was originally for voice and orchestra, and the text relates the story of a woman’s suffering (it would have helped to have a translation in the program). In its voicing and textures, it is French to the core. Ziegler found an ideal breathy vocal projection but overlaid her delivery with such a broad vibrato that pitches were ambiguous and lines wobbled.

The quartet’s most touching and heartfelt playing came in its pre-intermission performance of the andante cantabile movement from Mozart’s “Dissonance” Quartet, K. 465. It was played in memory of U-Md. faculty member and administrator Suzanne Beicken but might have also stood as the quartet’s real and best farewell.

Reinthaler is a freelance writer.