Johannes Brahms had several roles in Music: He was a pianist, he was a choir director, and he performed on tour to perform duets with violinist Joseph Joachim.
And yes, while he was a composer he did so in the shadow of a giant by the name of Beethoven. So… when Brahms decided to compose, he did so in stages.
His first stage was to compose two “serenades” to explore and learn how he wanted the strings, winds and later also the brass to fit together.
The first of these Serenades is really like a Brahms “Symphony #0”. Four major symphonies followed the Serenades.
Here for your enjoyment is the Serenade #1: