Alto
The word alto can mean: someone who sings lower than a soprano.  Usually females with lower voices are called contraltos.  A male alto is a man who sings in a special way called falsetto.  In England male altos sing in church and cathedral choirs.  In some countries like Germany it is tradition to have boy altos in cathedral choirs.  These will probably be boys whose voices will soon be breaking and are starting to get lower.