Gertrud Bertha Schoenberg (née, Kolisch; pen name, Max Blonda; 11 July 1898 – 14 February 1967) was an Austrian opera librettist.
She was the second wife of Austrian composer Arnold Schoenberg, whom she married in 1924, and the sister of his pupil, the violinist Rudolf Kolisch.
[5] She wrote the libretto for Schoenberg's one-act opera Von heute auf morgen under the pseudonym Max Blonda.
[7] After her husband's death in 1951 she founded Belmont Music Publishers devoted to the publication of his works, and was also a key figure in bringing about the premiere of Schoenberg's opera Moses und Aron.
[2] Arnold used the notes G and E♭ (German: Es, i.e., "S") for "Gertrud Schoenberg", in the Suite, for septet, Op.