Bass strings, made from nickel, stainless steel, or flatwound materials, provide deep, fundamental tones and influence playability. The earliest bass strings were flatwound, but roundwounds became the industry standard for their brightness and harmonic content. Key brands include Rotosound (Swing Bass 66), D’Addario (EXL and NYXL series), Ernie Ball (Slinky Bass), and La Bella (Deep Talkin’ Bass for flatwound lovers). Roundwound strings are bright and articulate, favored in rock and funk, while flatwound strings deliver a smooth, vintage tone for jazz and Motown. String gauge and scale length are crucial for tone and tension, especially in drop tunings or extended-range basses.