Lamothe had his first lessons from his mother and studied the piano and clarinet at the Institution Saint Louis de Gonzague in his native Port-au-Prince where he exhibited exceptional technical and compositional abilities from a young age.
[1] In 1910, German merchants in Haiti recognised his talents and funded a scholarship for him to go and continue his studies in Paris, France.
[1] Lamothe returned to Haiti in 1911, remaining there for the rest of his life; he taught and gave private recitals on the piano in his home.
[1] One of his notable works is entitled, La Dangereuse, a slow tempo piece with gentle, restrained dynamics, was warmly received by the Haitian aristocracy.
[1] Later in life, Lamothe encountered some serious financial problems, largely due to the fact he had not published many works internationally, only two, and even those were limited to Berlin and Paris, so he was not generating enough income to sustain a living.
Although little of his music was published even in his native Haiti during his life, after his death his family collected his manuscripts and had them printed privately.