Above, you see Finn's very best "lullaby harmonica." He also does "happy harmonica," in which he plays very fast while jumping up and down, and "sad harmonica," which is so mournful that he even made himself tear up once while playing.
These past weeks, as his harmonica playing has really taken off, I've become convinced that it is the perfect first instrument for little people. The hand-eye-ear coordination required is minimal, it always sounds good, and it immediately allows him to feel like a contributing member during family music time. You should hear Patrick and Finn play Billy Joel's Piano Man together - it's one of those situations that causes a mother to get a big, goofy grin on her face.
Finn is angling for a harmonica holder so he can play his green guitar (which is actually a ukelele) while keeping his harmonica humming.
Move over, Bob Dylan.