BJ has learned to whistle (at long last, after much practice). He has currently mastered a single whistled "note" and repeats it rhythmically, almost constantly, and is working on adding other notes to the repertoire so that he will have a tune. He's very proud of this accomplishment. It has not yet become annoying (I hope it stays endearing). It will also be interesting to see if he can still whistle once his two front teeth come in.
Since there is also a drum major camp going on in our building, we are hearing lots of whistles in the vicinity. It gave me an unexpected burst of nostalgia to hear the rhythmic tweets -- though I could no longer recall what each of the patterns symbolized -- and we've been having fun watching the majors with their batons, twirling and tossing. Ah, the memories of being in the marching band. Nothing quite like that combination of enthusiasm, precision, energy, and en-masse earnest geekiness. I think few things in life are as sincere as a really good marching band.
Case in point: OK Go's Marching Band Version of This Too Shall Pass
This one is a family favorite, and when I called that up on YouTube to get the embed code, BJ came over to watch it with me. And proceeded to mono tonally (but mostly rhythmically) whistle along throughout the song. Pretty danged cute.