FORT WORTH — How about a little music for classical guitar four hands?That was among the many unexpected treats offered in the performance by Duo Siqueira-Lima at University Christian Church on Thursday night.Brazilian husband and wife team Cecilia Siqueira and Fernando Lima strolled, strutted and pranced through a program of works by composers ranging from Domenico Scarlatti to Astor Piazzolla, before concluding with one of the most amusing (and impressive) encores one would ever hope to see in an evening of classical guitar music.The opening half of the concert presented by the Fort Worth Classical Guitar Society was arranged almost chronologically, beginning with a piece by Baroque harpsichord master Scarlatti and finishing with works by Spaniards Joaquin Rodrigo and Brazilian Manuel da Falla, with a trio of Felix Mendelssohn’s Songs Without Words in between. All were delivered with a great deal of technical precision while also managing to reflect a lot of style.But far and away the best of these initial offerings was a Chaconne in G by G.F. Handel. The virtuosity displayed in that particular work was just jaw-dropping. Their performance of this theme-and-variations work began easily and innocently enough. But with each variation, the listener was pulled deeper and deeper into the piece until the pair had us on the inside of it looking out. And what a splendid view it was.As a whole, the first half gave a sense of how these players differ from other guitar duos, which usually strive to maintain two distinct voices and often arrange pieces in a call-and-response type of interplay.Siqueira-Lima worked that side of the street on occasion. But what sets them apart from the pack is an unusually soft, yet highly resonant sound that features a great deal of unison and harmonizing playing. Their overall skill packages seemed surprisingly equal. But Lima demonstrated an exceptional ability to tattoo out clear, ringing notes, while Siqueira showed a particular gift for quick, agile runs and fills. The second half of the concert jolted the audience of about 250 into times closer to the present with a series of selections by South American composers that was tilted more toward popular forms (Brazilian dances, for example) than traditional classical works. It opened with Aquarela do Brasil by Ary Barroso — a piece we know as the big band era favorite Brazil. It featured a clever arrangement by the duo, who arranged nearly all of the works on the program, and was a lot of fun. And for that reason, it had the feel of a number that should have been saved for an encore.But not at this concert.Because the duo wrapped things up with one of the funniest — and most dazzling — final bows you are ever likely to see at a classical guitar recital.After being called back to the stage by sustained applause, Siqueira retook her seat, but Lima did not. Instead, the lanky guitarist draped his arms around his diminutive spouse and they proceeded to play Tico-Tico together on a single guitar . The zippy little Brazilian dance tune by Zequinha de Abreu (which you would probably recognize if you heard it) was played perfectly with four hands strumming and fingering as if they were two. Often, one of the players was working the fret board while the other picked out the notes, which has to be even trickier than it looked. So the concert, which had been so outstanding throughout, found a way to top itself with a finale that was visually comic and aurally sensational. About the only shortcomings of the presentation was that it did not really exploit Valentine’s Day in any way, Siqueira’s remarks to the audience were difficult to understand, and the program notes, which appeared to have been translated by a computer, resulting in some pretty hilarious prose.