SONATA NO.1 OP.78 in G major 'Regen-Sonate'
Brahms composed his g-major sonata op.78 in his summerhouse in Pörtschach during the summers of 1878 and 1879. After finishing the sonata he presented it to his friend, one of the most outstanding violinists of all the times, Joseph Joachim. In the same period, Joachim and Brahms were busy with final details and bowings of the violin concerto Op. 77. Structure-wise we can notice some similarities between op.77 and op. 78, such as large phrases, big legatos, melodic lines, etc. Comparatively, the sonata is less challenging than the concerto, in its violinistic demands.
The first movement has the tempo indication of Vivace ma non-troppo (lively, but not too much). This tempo marking is not so often used in such a lyric, poetic context. The theme starts with a dotted rhythm, which is the rhythmic figure that every movement of the sonata is based around.
The second movement starts with Adagio in E-flat major after comes the second theme piu andante, which sounds like a funeral march in E-flat minor due to its dotted rhythm and harmonies.
During the same period, when Brahms was composing this sonata, he received two letters from Clara Schumann, where she was writing about her son, Felix's death and her sorrow. This sonata, especially this movement, can be indirectly connected with Clara's current mood.
The third movement is Allegro molto moderato. Even though it is in G-minor this movement is very bright and lively. The dotted rhythm "mood" of Brahms inspired him to use once more, the motif of his two songs op. 59 to Klaus Groth's (19th-century German poet) "rain" poems, Regenlied and Nachklang. That's why op.78 is often called "Rain Sonata".
The first performance was in 1879 in Bonn, by the husband and wife Robert (violin) and Marie (piano) Heckmanns.