A bad case of tendonitis ended Loreta Kovacic's promising piano career, but didn't stop her from leading a charmed musical life. To spare her wrist she plays an electronic keyboard and the melody horn. She also sings. Her show at the Boom Room Saturday night includes “songs from countries that I like: Brazil, Cuba, Italy” and her own compositions. Many of her songs are about local figures, such as the Art Guys. The show has a distinctively cabaret feel to it, with all the notes filtered through her larger-than-life personality.