Philip Gray
The eponymous young musician of the title, Philip Gray is an adolescent boy whose father dies, leaving him an orphan with only his clothing, a violin, and some shares in the Excaliber Gold Mine in California (which might be worthless). He is a handsome, intelligent, mature young man who has been studying the violin for perhaps three years and who can play better than most self-taught musicians. After his father dies, Philip escapes from Joe Tucker's alms-house and makes music to earn a living.
Squire Pope
Benjamin Pope, or "Squire" Pope, is an important man in town who is used to getting his own way. When Philip's father dies bankrupt, Pope tries to liquidate all his assets at auction, and resents the fact that Philip succeeds in hiding his violin. An amoral and greedy man who has Philip imprisoned in Joe Tucker's alms-house and who later seeks to defraud Philip of his earnings, Squire Pope has a wife named Almira and a niece named Caroline Cunningham.
Squire Pope is the novel's primary antagonist.
Almira Pope
Squire Pope's wife is a kindly but simple woman who defers to her husband. She is soft-hearted and has no predatory ambitions involving Philip, but she is completely dominated by Squire Pope, whose will prevails in the household.
Caroline Cunningham
Caroline is Squire Pope's niece. She becomes aware of Philip when he is giving a concert in a neighboring town, and prevails upon the Squire to take her. This is how Squire Pope becomes aware of Philip's skill. Although she is attracted to Philip and appreciates his talent, her character serves no purpose except as a plot device to reunite Philip with his nemesis the Squire.
Nick Holden
Nick is a secondary antagonist: an older boy described as "coarse" and rough-looking. Not particularly intelligent or well educated, he believes he could be successful with the girls if he only possessed Philip's violin. He therefore tries to buy it at auction, but fails.
Frank Dunbar
Frank is a boy about Philip's age who sympathizes with him and who prevails upon his father, Frank Dunbar, to buy Philip's father's watch at auction and to keep it for Philip until he is of age to claim it. He helps Philip escape from the alms-house and helps him overcome a robber who is threatening Farmer Lovett.
Joe, Abigail, and Zeke Tucker
The Tucker family run an alms-house or poorhouse, where the indigent citizens of the town are lodged at public expense. Squire Pope arranges for Philip to be lodged with Joe Tucker after Philip's father dies, so that Joe can make money by feeding him poorly and Pope can get his hands on all Philip's late father's assets. The scheme fails when Philip escapes.
Abigail Tucker is an insomniac who is similar to her husband in terms of acquisitive greed. Unlike Almira Pope, who is a benevolent foil to her husband, Abigail is a conspirator who tries to make sure Philip does not escape. However Zeke, her son, is a thief.
Overall, the Tucker family is dishonest and sadistic with no redeeming qualities.
Farmer Lovett
Farmer Lovett is a wealthy man whom Philip and Frank rescue from a robber. In gratitude, he gives Philip five dollars in cash and fifty dollars more in an envelope to be opened later. This money saves Philip and allows him to pay his creditors after he is defrauded by Lorenzo Riccaboca.
The scene in which the boys save Farmer Lovett is a classic Horatio Alger trope: the hero commits an act of bravery and is rewarded by a grateful older man who acts as a mentor and who provides the hero with a necessary opportunity.
Lorenzo Riccaboca
"Professor" Lorenzo Riccaboca is a con artist. Described as a tall man with long, black hair he appears to be a poet of some sort. A hearty eater and an extrovert, he describes himself as an "elocutionist" or a professional reader of dramatic poetry. After hearing Philip play, he books himself and Philip in the next town as a team, without Philip's consent, and walks away with all the money leaving Philip to pay the hotel bill and other expenses. Although Philip and his allies Mr. Gates (an inkeeper) and Mr. Perry (a landlord) eventually catch up with him, Riccaboca is not trustworthy.
Henry Taylor
Henry is a clueless young man from New York who has run away from his father Alexander and his sister Jenny, with the intention of "killing Indians". He runs out of money and depends on Philip for food and transportation to return home.
Winuca
A man of the First Nations, Wincua is the first "Indian" Henry and Philip meet when they accidentally fall asleep in his cabin, thinking it abandoned. A kind man despite his muscular and aggressive appearance and imperfect English, Winuca cares for the boys and feeds them, and behaves like a host. He accepts a gift of a folding-knife from Philip, who instinctively guesses the most adult and honorable way of acknowledging a gift in Winuca's culture. The encounter with Winuca pleases Philip, who has made a new friend, but Henry is completely terrified and understands how ridiculous it is for him to aspire to kill Indians. He returns with Philip to New York with no further complaint.
Alexander Taylor
The father of Henry and Jenny Taylor, Alexander is a wealthy man who is powerless in terms of his wayward son, Henry, whom Philip rescues and returns to New York. In gratitude, Alexander Taylor arranges for Philip to continue his education. He is another example of the successful male mentor who appears in many Horatio Alger novels.
