The IMF Art Society presented Paraguayan classical guitarist Berta Rojas in a recital featuring South American, Cuban and Spanish composers Thursday evening in the Gallery of the International Monetary Fund. Opening with three Venezuelan waltzes by Antonio Lauro, Rojas's tender phrasing suggested a pastoral quality. The contemporary rhythms in Juan Manuel Acevedo's "La Jornada" and several other songs were marred by a persistent electronic feedback problem on certain treble notes. Rojas's technique was flawless, however, and begs for the purity of no amplification.

"The Black Decameron" by Cuban composer Leo Brouwer is based on erotic tales from Africa, Rojas said, with a hint of mischief in her eyes, "so close your eyes and let the images come to you." The "Decameron's" three movements showed off Rojas's technique, with precisely carved open chords and threads of melody played forcefully then lightly echoed. "La Muerte del Angel" by Argentine composer Astor Piazzolla demonstrated that Rojas exploits the reverberation of sound completely. Between flurries of raging dissonance, she slowed her hand to use every receding nanosecond of a note's life.

It takes a skilled guitarist to toss off the demanding reaches in the Agustin Barrios classic "Un Sueno en la Floresta" while sustaining a fingered tremolo. The Peabody trained Rojas dispatched the song elegantly, with a tremolo like liquid crystal, so seamless that one could imagine a balalaika player had joined her onstage.