VILLA-LOBOS: Piano Concertos. Cristina Ortiz, piano; Royal Philharmonic Orchestra, conducted by Miguel Gomez-Martinez. London 430 628-2 (two compact discs). Who would know from our stunted concert repertory that Villa-Lobos wrote five piano concertos (and let's not even start on the 12 symphonies . . . )? Granted, these big, extravagant late works are inconsistent in inspiration and execution, but overuse has taught us to accept many other equally uneven works. Imagine the sensibilities of Rachmaninoff filtered through the craft of Prokofiev, and you have an idea of the character of these zesty, virtuosic bangers, full of tunes and dazzle. Ortiz delivers them with incisive strength, supple lyricism and uncompromising spirit, despite some splattered passages. There is also altogether more music in the vivid, over-the-top accompaniments than the frazzled royal fiddles seem prepared to handle. Gomez-Martinez keeps his messy orchestra generally on the pace, and elicits some insinuating obbligato solos.