Szymanowski’s two violin concertos usher you into a world of Polish music very different (as he said himself) from Chopin’s waltzes and mazurkas. Concerto No. 1, from 1916, shimmers with exotic “orientalism” as it drifts rhapsodically through sumptuously spangled scoring. No. 2, from 1932, is earthier, with an astringency and vigor drawn from rural Polish folk-dance. But they’re both distinctly Szymanowski, and the artists here are well-versed in his idiom. Tasmin Little glistens in the stratospherically high-lying violin part, with a clean edge to her tone that stops the music’s stream-of-consciousness flow from slithering about too much (her playing in the No. 2 cadenza is spectacular). And Edward Gardner gets vibrant colors from the BBC Symphony Orchestra. The Violin Concerto by the lesser-known Mieczysław Karłowicz is more conservative: composed in 1902, it’s a cheerfully Romantic homage to Tchaikovsky, but well worth exploring.