How do Johannes Brahms’s symphonies differ from Anton Bruckner’s symphonies?

The symphonies of Johannes Brahms and Anton Bruckner represent distinct approaches to the symphonic form during the Romantic era, despite both composers being essentially conservative in their adherence to traditional structures.1

Key Differences:

• Accessibility and Style: Brahms’s symphonies are highly individual, appealing upon first hearing, and rewarding to revisit. In contrast, Bruckner’s symphonies are not immediately rewarding and are characterized by a sense of density and monumental scale.1
• Orchestration: Brahms’s orchestration is noted for its detail and balance, serving the lyrical flow of his melodies without ever being flashy. Bruckner, conversely, utilized heavy orchestration and Wagnerian harmonies, often employing terraced dynamics where groups of instruments are sounded in alternating, contrasted blocks.12
• Form and Development: While both maintained the four-movement format, Brahms focused on rigorous contrapuntal craftsmanship and the consistent development of melodic themes. Bruckner’s symphonies are known for their excessive length, large-scale repetitions, and a unique sonata form that often incorporates three contrasting themes in the exposition.12
• Philosophy: Brahms sought a balance between early 19th-century expression and traditional techniques, often emphasizing architectural clarity. Bruckner’s work is deeply personal and spiritual, described as being charged with the grandeur of God, and he frequently revised his scores throughout his life.12