Violin and music imagery
Philip's violin is very important to him, and he has a deep and abiding love of music. He practices frequently, and is skilled enough to earn money by playing. To be that skilled in his mid-teens is unusual, and so the talented amateur attracts a lot of attention as a young prodigy. Young women in particular respond to Philip's playing, possibly because his joy in the music is something that is obvious to everyone who hears him.
Buggy and driving
Driving, and being allowed to drive, was as much of a privilege in Horatio Alger's day as it is in ours, and learning to drive was considered a rite of passage toward adulthood. However, in The Young Musician automobiles are almost unknown except as curiosities, and most farmers rely on horses and wagons. To own or to have access to a buggy simply for driving about to run errands is a luxury. The impoverished Philip therefore walks everywhere, except when he is offered a ride.
Wealthier characters, such as Mr. Gates, own buggies and ride about in them. When Mr. Gates allows Philip to take the reins and drive, Philip is being given a rare treat and a privilege. Mr. Gates is also showing his trust in Philip and his respect for the young man.
Clothing and success
In Horatio Alger's world, clothes really do make the man (or the boy). One of the things Philip first notices about "Professor Lorenzo Riccabocca" is his outlandishly formal style of dress, with a wide collar and vest. The outfit appears too formal for a man traveling alone on foot, and to a more sophisticated reader or character it's obvious that the man is up to no good. Yet Alger also uses clothing as a representation of class. At the end of the novel, Alexander Taylor sends Philip to his tailor to be measured for clothing suitable for his new life as a student at a private boarding school.
Letters and notes
Although telegraph communication existed, most long-distance communication of the era required that people write to one another. Philip pens a letter to his friend Frank Dunbar prior to his first successful concert, and it is a note from Farmer John Lovett containing a gift of money that allows Philip to pay his debts after Lorenzo Riccabocca runs off with all the money from the concert. The letter Philip requires Henry to send to his father contains all the necessary information to convince Alexander Taylor that Philip is an intelligent, sensible, and safe companion for his son.
Another form of written communication is the dishonest playbills Riccabocca causes to have printed up, wherein he exaggerates and lies outright about himself and about Philip. Philip dislikes the untruthful advertisements.
