This is the recorder Peter always kept by his side in the movie. It represents his past, and how he always carries it everywhere with him, whether it be physically when he listens to the music, or symbolically when his actions are influenced by his childhood.
If you’re anything like me, you sometimes get to the day of a rehearsal without any coherent plan (I’ve talked about this problem before; it’s a perennial one). So I thought you might find it useful to have a basic toolkit of ideas for warm-ups for those occasions when you just feel totally uninspired and …
How To Sing: A 1902 Illustrated Guide from the Great German Opera Singer Lilli Lehmann
Not all of it holds water anymore today, but still: A recommendation for every aspiring classical singer, especially since you can download the book for free: How To Sing: Lilli Lehmann's Illustrated Guide, 1902 | Brain Pickings