Born in Schöningen, she originally trained as a pianist, at Braunschweig and at the Musikhochschule Hamburg.

However, she made her debut as a contralto at the Staatstheater Braunschweig, as Irmentraud in Lortzing's Der Waffenschmied in 1951.

Pilarczyk became a specialist in works of the twentieth century, including works by Richard Strauss, Salome and Die Frau ohne Schatten (as the Dyer's Wife), Prokofiev's The Fiery Angel, Luigi Dallapiccola's Il prigioniero, Stravinsky's Oedipus rex and The Flood, Alban Berg's Wozzeck and Lulu, and Schoenberg's Erwartung and Von heute auf morgen.

She appeared in Zürich, Berlin, at the Royal Opera House, Covent Garden (as Salome in 1958), Florence (Erwartung and Wozzeck), the Glyndebourne Festival (as Composer in Ariadne auf Naxos by Strauss, 1958), Paris Opéra (Wozzeck, 1963, and Von heute auf morgen, 1967), La Scala (Lulu, then The Flood, both in 1963), and Vienna.

Opera Depot has issued her 1963 performance of Puccini's Il tabarro, conducted by Alberto Erede, on Compact Disc.