There are (have been) some great Portuguese singer songwriters. A must-listen is José Afonso, especially Cantigas do Maio and his recordings of (Coimbra-style) Fado. Sergio Godinho, Vitorino, José Mario Branco are among my favorites as well. In the 1990s, Madredeus made a few lovely records. There’s a whole bunch of newer Lisbon-style Fado singers with various takes on the tradition (Marisa, Ana Moura, Carminho…) who may be worth exploring, but I haven’t listened to much of their music.