Complex sentence: Both were friends of Brahms who composed the song "Geistliches Wiegenlied" for the occasion of their wedding; he withdrew it, however, but sent it again a year later for the baptism of their son, named Johannes after Brahms.
Split into simpler sentences: Both were friends of Brahms who composed the song "Geistliches Wiegenlied" for the occasion of their wedding. He withdrew it, however, but sent it again a year later for the baptism of their son, named Johannes after Brahms.