By Martha Ullman West

At Mississippi Pizza a week ago last Friday, I saw one of the most musical dance performances I’ve seen in years, delivered with all her heart by a dancer named Sadie (last name unknown), age about five, as she was propelled to her feet by the equally heartfelt music of the Backyard Blues Boys.

Pigtails flying, jumping up and down in perfect rhythm, spinning around at will — children are marvelous improvisers — this little girl could have had no idea, or at least I hope had no idea, what the musicians were playing and singing about in songs like Saint James Infirmary and their own Rainy Day Blues. What she did know was that that sound, those rhythms, compelled her to move.

So what do we mean when we say a dancer is musical?

Sometimes we mean she’s had musical training: Maria Tallchief, for example, the great  ballerina who was George Balanchine‘s third wife, had extensive training as a pianist when very young and could have gone either way. This was also true of Balanchine, potentially as fine a musician as he was a choreographer.

But more often we mean a dancer feels the music in her brain and her muscles, deeply and profoundly, and joyously. That was young Sadie, dancing and improvising along with the Backyard Blues Boys: Lucas Biespiel, violin and singer; Wade Hills, rhythm and slide guitars, harmonica; Reuben Unrau, lead guitar; Garren Epley, drums and percussion; Louie Leager, standup and electric bass; Jason Morrison, keyboards. Two not-boy singers perform with the band, Samantha Hooper and Jillian Looney. And all of them are kids, if old by Sadie’s standards: they’re high school seniors who formed this terrific group a couple of years ago.

This performance, which at its end had me and half of the audience on our feet, boogieing down, was also a perfect illustration of the value of live music, for any kind of dancing  — theatrical, social, you name it.

Now the disclaimer: I’ve known Jason Morrison since he was about Sadie’s age and have enjoyed hearing him tickle the ivories for just about that long, practicing classical piano, and now improvising with blues. I recommend catching the Blues Boys’ next gig, and maybe, just maybe, Sadie will be there, dancing as well. Check their website: www.backyardbluesboys.com