Ander can sing

The last couple weeks I’ve been treated to a wonderful sound:
My 2yr Ander singing notes in pitch, go-ing ‘ah’ ‘ah’ in half-octave changes, sometimes only for a few notes, sometimes going on for several minutes.

He only ‘sings’ when playing by himself…he won’t ‘perform’ on command regardless of my coaxing, but I do love that sound.