Great selection, ON :tiphat:
Hmmm ... I can't find any German composers with the letter "I", so perhaps we should move on:
Gustav Uwe Jenner (1865-1920) He studied composition with Brahms for 7 years, apparently the only pupil (in that subject) to do so with the famed composer. Later, upon Brahms reccomendation, he became director of music at Marburg university.