Paula Robison is a wonderful classical flutist, but she also clearly loves Brazilian music. For Rio Days, Rio Nights, she has chosen some of Brazil’s finest musicians to back her up for an exploration of bossa nova and earlier popular Brazilian forms. Guitarist Romero Lubambo, percussionist Cyro Baptista, and bassist/cavaquinho player Sergio Brando also lend their voices and arrangements to Robison’s recording. The result is a deceptively simple sound. Antonio Carlos Jobim’s “Chovendo na Roseira,” (“Rain in the Rose Garden”) is a natural for flute instrumentation, although the reverb detracts from Robison’s beautiful tone. Two pieces by the Brazilian musical elder statesman and flautist Pixinguinha, along with the demanding “Frevendo” by A’cio Fl’vio, may well qualify Robison for an honorary Brazilian citizenship.