Born in Paraguay in 1885, he spent a frustrating career as a guitarist-composer, often mocked for his unconventional repertoire and for using metal guitar strings rather than the conventional gut. A true original (he was the first classical guitarist to make recordings), Barrios also reinvented himself in his mid-40s as a Guarani tribal chief, performing in native costume and calling himself Cacique Nitsuga Mangoré, "the Paganini of the guitar from the jungles of Paraguay." Barrios died, largely unsung, in 1944. But he left behind some of the most engaging and beautifully crafted guitar music ever written, and on Saturday evening the gifted Paraguayan guitarist Berta Rojas presented an all-Barrios program at Westmoreland Congregational Church, as part of the always interesting John E. Marlow Guitar Series. Rojas clearly has Barrios´ music deeply in her blood; playing entirely from memory, she traversed the composer's stylistic range, from the poignant "El Ultimo Canto" through classically inspired works like "Estudio de Concierto" and "Allegro Sinfonico" to pieces like "Julia Florida" and "Jha che Valle" (with their roots in Latina American folk music) and Barrios´ extraordinarily beautiful masterpiece, "La Catedral." And when Rojas is at her best, there may be no better Barrios interpreter alive. Often in the faster works, she tended to push tempos to the brink, smearing the details. But on the whole, these were intimate, introspective performances (the moving "Choro de Saudade" seemed to come directly from her heart), rich in subtle colors and intuitive understanding of Barrios´ complex personality.