The song begins piano-backed, and leads into a chorus backed with percussion, guitar, piano and strings.

The soundtrack version has the same arrangement as the original, however has embellished background music in part (such as added harp) and extended instrumental sections.

The lyrics express the love for another, likening them to "sunbeams filtering through leaves," and saying that they had given the song's protagonist hope.

[3] The song begins with a 1:50 introduction in three steps: first Kokia sings Japanese lyrics against background sound effects and the piano.

[4] Both the standard Japanese and coded section have lyrics which bring up many natural images (such as a "sea of sound," "drop of water," "quiet forest," etc.).

A music video was filmed for the leading A-side, "Ai no Melody," directed by Takatoshi Tsuchiya (土屋隆俊).

[7] A vote was taken on Kokia's official site as to which actress out of five potentials should be shot as the main character in the video, with Sachi Natsuo winning.

The second is a mini-drama performed by actor Ryō Katsuji (the voice of Agito in Origin: Spirits of the Past) and actress Sachi Natsuo.

Katsuji's tree begins to grow, and a leaf falls on Natsuo as she watches the film in the cinema.

The final scene (after the song has stopped playing) features Natuo's character walking past Kokia as she leaves the cinema.

[10] Because of this, "Ai no Melody/Chōwa Oto (With Reflection)" is Kokia's third best selling single, after "The Power of Smile/Remember the Kiss" and "Kawaranai Koto (Since 1976)" in 2003.