The Osmonds, The Beach Boys, The Jackson 5 are all famous family bands. Will the Henry Acker Trio join the pantheon of family musical groups? You can be the judge for yourself, as the Trio is performing at the Loring-Greenough House on May 6. The Trio is headlined by 13-year-old Henry Acker, who is a gypsy jazz guitarist in the style of Django Reinhardt with abilities far beyond his years. "My brother Dana and I attended Berklee and have been performing as a jazz trio around Boston for many years.