The phrase "act as composer" is correct and usable in written English.
You can use it when referring to someone taking on the role or responsibilities of a composer in a specific context, such as music or writing.
Example: "In this project, I will act as composer, creating the original score for the film."
Alternatives: "serve as composer" or "function as composer".
Conti, who has acted as composer on every Rocky film except Rocky IV (which was instead helmed by Vince DiCola when Conti had other commitments at the time), chose to compose the score almost entirely from musical themes used in the previous movies.
Act as quickly as possible.
"I typically act as the composer and the orchestrator and the musical director, because in a rock band those three things aren't separate roles, those are just things that you do," said Mr. Malloy, who is classically trained but has also played in a wide range of jazz and rock ensembles.
He's the real wizard though, I mostly act as a "composer" of sorts.
Frears needed someone who could play piano as well as act – his composer, Alexandre Desplat, tipped him off about Helberg.
As Schmid, who also acted as a composer, wrote in a 1744 letter from San Rafael de Velasco: Some Jesuit institutions still exist in the Chiquitania.
The American pianist Jonathan Biss is putting his passion for Beethoven to intriguing uses: following his intellectually-provocative eBook Beethoven's Shadow he's launched an online course on Beethoven's sonatas which has reached 100,000 people, and he's commissioned concertos from five composers to act as counter-weights to Beethoven's five.
Rimsky-Korsakov tutored Stravinsky mainly in orchestration and acted as the budding composer's mentor, discussing each new work and offering suggestions.
On the musical front, Sony's Flow Machines software, which can learn and reproduce musical styles, includes an AI composer that can act as an assistant to human musicians.
