ANGIE MILLER

LOSANGELES— Angie Miller’s poise and confidence seem as effortless as her high notes.

The 19-year-old finalist from Beverly, Mass., took guest mentor Harry Connick Jr.’s teasing in stride when he claimed that his family — Connick aside — loves her voice. Earlier this season, when given the choice of picking a song from a playlist or an original for the show’s crucial Hollywood auditions, Miller went with her own tune, You Set Me Free, although only family and friends had heard it.

“I’m really confident in myself as an artist and the music I do,” Miller said during a break in rehearsals for this week’s showdown. She did seek a less partial opinion, from American Idol vocal coach Matt Rohde, and no punches pulled.

“I looked at Matt and said, ‘You need to tell me if this song isn’t good enough. Tell me if it’s a bad idea,”’ she said. He applauded it, and so did the judges who gave a standing ovation to the piano-playing brunette with the wide smile.

One her most rousing Idol performances came after the Boston Marathon bombings, when she dedicated the song I’ll Stand by You to “my home, Boston.”

It was in childhood that she suffered ruptured ear drums and impaired hearing, Miller said. The problem worsened when one ear drum deteriorated and the doctor who diagnosed it last year recommended that she undergo skin graft surgery post-”Idol.”

Miller, who’s gotten used to adjusting on stage for her condition, is facing that prospect with the same public composure she displays toward her Idol experience.