Born Francisco Xavier da Cruz in Mindelo and confined to a wheelchair from youth by bone tuberculosis, B.Léza became the composer most credited with modernizing morna, absorbing guitar styles that Brazilian and Argentine sailors brought through Mindelo's port and working them into what Cape Verdean musicians call the meio-tom brasileiro — passing chords that gave the genre its bittersweet harmonic depth. He wrote dozens of mornas and coladeras across the 1930s–50s, several of them (including "Miss Perfumado" and "Lua Nha Testemunha," reportedly composed on his deathbed) later carried worldwide through his niece Cesária Évora's recordings.