António Maria Chéu was born in Beja, in the parish of Salvador, on 3 June 1866. Regarding his early years, we know that he was a carpenter until the age of 13.
In 1880, at the age of 13, he joined the Army as a volunteer apprentice musician for ten years at the 17th Infantry Regiment, in Beja. At the age of 19, he transferred to the 7th Infantry Regiment, in Tomar. At the age of 29, he was promoted to 1st class musician (Bombardon) and transferred to the 12th Infantry Regiment, in Guarda.
In 1898, at the age of 32, he was transferred to the Navy with the rank of Director of Music. After passing an examination, he was admitted as head of the 'Charanga da Armada' and integrated into the Seamen Corps. At the time, the Navy Band had around 30 musicians. So, as far as it is known, he became the first Portuguese conductor of the Navy Band.
In 1903, at the age of 36, he was promoted to Sub-lieutenant of the naval service auxiliary staff, the first time a head of the Navy Band had been promoted to officer.
Also in 1903, he conducted the Band in a concert after the dinner held at the Necessidades Palace for King Edward VII of England in which, among other pieces, the Band played 'Cantos Populares Portuguezes' by Rodriguez and 'Hino Luso-Britânico', written by him.
Also in 1903, he became the first Portuguese maestro to record those that are, as far as we know, the first recordings ever made in Portugal. These include two of his works: 'A Vontade' and 'Anglo-luso', besides the then Portuguese Anthem ('Hino da Carta'), in a total of 26 pieces. He is the first musician from the Navy Band who is known to have written his own compositions.
On 1 June 1911, at the age of 44, his request to have his seniority as an officer since 7 September 1899 considered for retirement purposes was granted by ministerial order. In July of that year, the newspaper 'Eco Musical' wrote that it was António Maria Chéu who transformed the charanga into a band.
He often conducted the Band in concerts at Tapada da Ajuda and Pena de Sintra during the summer holidays of the Royal Family. According to family members, he was cherished by the Royal family and a friend of Viana da Mota.