Ivan Langstroth was born in California. he went to Germany for his musical education where he studied composition under Juon and Humperdinck. Lhevine was his piano teacher. In 1915 he wrote a piano concerto in C minor. He toured Europe for some years as a pianist. Is anything known about this piano concerto, is it typical of the period in which it was written?
One thing I can say is that he wrote a second, in D minor, opus 45, though that doesn't help very much. (See Inventory of the Ivan Langstroth Collection (http://www.oac.cdlib.org/view?docId=tf596nb1w7;style=oac4;view=dsc).)