Barbra Streisand and Donna Summer are two of the most influential figures in 20th-century pop and disco music, respectively. Streisand, known for her powerful mezzo-soprano voice and Broadway background, brought theatricality to pop music. Summer, dubbed the "Queen of Disco," significantly influenced the genre with her four-octave vocal range and sensual style. Their 1979 duet "No More Tears (Enough Is Enough)" showcases their distinct vocal styles and remains a significant milestone in both of their careers.