He began his duties by going through many short choral works of the older and modern masters. With other musicians at Court much chamber music was played, in fact almost the entire repertoire. The young musician soon became a favorite at Court, not only on account of his musical genius but also because of the general culture of his mind. He could talk on almost any subject. "Whoever wishes to play well must not only practise a great deal but read many books," was one of his favorite sayings. One of his friends said, of meetings in Brahms' rooms at night, when his boon companions reveled in music: "And how Brahms loved the great masters! How he played Haydn and Mozart! With what beauty of interpretation and delicate shading of tone. And then his transposing!" Indeed Johann thought nothing of taking up a new composition and playing it in _any_ key, without a mistake. His score reading was marvelous. Bach, Handel, Mozart, Haydn, all seemed to flow naturally from under his fingers.
The post in Detmold only required Brahms' presence a part of the year, but he was engaged for a term of years. The other half of the year was spent in Hamburg, where he resumed his activities of composing and teaching. The summer after his first winter in Detmold was spent in Göttingen with warm friends. Clara Schumann was there with her children, and Johann was always one of the family--as a son to her. He was a famous playfellow for the children, too. About this time he wrote a book of charming Children's Folk Songs, dedicated to the children of Robert and Clara Schumann. Johann was occupied with his Piano Concerto in D minor. His method of working was somewhat like Beethoven's, as he put down his ideas in notebooks. Later on he formed the habit of keeping several compositions going at once.
The prelude to Johann's artistic life was successfully completed. Then came a period of quiet study and inward growth. A deeper activity was to succeed. It opened early in the year 1859, when the young musician traveled to Hanover and Leipsic, bringing out his Concerto in D minor. He performed it in the first named city, while Joachim conducted the orchestra. It was said the work "with all its serious striving, its rejection of the trivial, its skilled instrumentation, seemed difficult to understand; but the pianist was considered not merely a virtuoso but a great artist of piano playing."