He began composing early on. He began to compose his first piano concerto in 1860 when he was 15 years old. It was premiered in 1861 in Vienna by his teacher Julius Epstein. He also wrote for solo piano, chamber music, opera and lieder. He bacame a friend to many of the musicians in Vienna of the time, most notably Johannes Brahms and Gustav Mahler.
Brüll wrote two piano concertos, both works of his youth. The Konzertstück was written later in his life, in 1902. Brüll remained a conservative composer and never embraced any of the experimentation of the turn of the 20th century. Some of what a critic that attended the premiere of the piece had to say about the work:
"In the beautiful Andante, full of gentle orchestra color, we wander among the German pine forests, several times hearing the ominous rustle of cedars of Lebanon from distant times. The composer celebrates his morning worship alone until the cheerful Allegro leads him back to the bustle of happy people."
