Two important things to remember about Dash at four (and a half, if you ask him) :
1. He will only dance if he is wearing pants. Which is horrible in the Summer because he is nearly always wearing shorts & he is moved to dance to Every. Single. Song. that comes on the tv or radio. I'm now trained to run to his room for a pair of sweats when I hear the opening chords of anything. Because otherwise, the kid will literally start to dance, glance down & say, "oh, shorts." and then proceed to SIT HIS ASS BACK DOWN. It's heartbreaking.
2. He's super tic-y, this kid. We're not worried because they're all transient & his mom is a nutbag, too. But the current tic is too good not to make note of: he started tracing shapes with his head (imagine a kid looking at the tv--or anything, really--and just moving his head in all different directions to "trace" an object with his nose or chin or something). I have this compulsion, too (mine also involves counting of lines and the everlasting quest to reach a multiple of 10. see above in re: nutbag), so I told him about using your forefinger & thumb to trace whatever shapes you need without drawing attention to yourself. He hasn't mastered the more subtle maneuver, but he is now "tracing" on the table with these huge, magnificent gestures. It is awesome to watch.