PALERMO – The mobile home off a dirt road looks ordinary from the outside.

Inside, though, it shimmers with sound as 10-year-old Caleb Jordan Sparks plays piano pieces by his favorite classical composer, Ludwig van Beethoven.

Or 20th-century American Robert Starer.

Or Caleb himself, who is also a composer.

His “Variations on a Winter Storm” won third prize in Category I: Young Composers up to Age 13 at the 2011 Young Composers’ Festival, held in January.

“Variations” is a rhythmic piece reminiscent of Starer’s work. Caleb said his teacher, Bridget Convey of Hallowell, suggested that he enter the Boston contest, which is sponsored by the Bagaduce Musical Lending Library in Blue Hill.

Caleb began playing keyboard around age 5, after sitting by as older brother Angelo took piano lessons. Caleb played by ear before he learned to read music, said his mother, Lisa Sacks.

Lisa and Daniel Sacks are pleased that he has something he likes to do and is good at — especially, his mother said, because he’s been diagnosed with attention-deficit/hyperactivity disorder.

She urges parents of other children with ADHD to find something their children can focus on, so that their differences from other kids are positive as well as negative.

Caleb and Angelo are home-schooled. Lisa Sacks said the Grace Academy home-schoolers’ cooperative in China plans a musical and Caleb has been invited to be the accompanist.

Caleb said he seldom gets nervous about playing for people outside his family: “It’s fun.”