Complex sentence: Summer eventually became fluent in German, singing various songs in that language, and participated in the musicals "Ich bin ich" (the German version of "The Me Nobody Knows"), "Godspell" and "Show Boat".
Split into simpler sentences: Summer eventually became fluent in German, singing various songs in German. She participated in the musicals "Ich bin ich" (the German version of "The Me Nobody Knows"), "Godspell" and "Show Boat".